Linux vs. Windows on HCC - a study

I originally posted this in artemm's thread, but since he actually did something different (HCC-only vs. all projects on Linux) I thought this deserved its own thread.

What I'd like to do here is find out which OS is best for crunching. This is done by comparing data from one or multiple machines. I started off by calculating some numbers for you - Windows 7 x64 vs. Ubuntu 10.04 x64 with no changes to the hardware (clockspeed etc).

All numbers are from the "result statistics" page on the WCG website. I just picked the first 15 (or mostly 30) valid HCC WUs, added them up, and divided through the number of WUs taken into account to generate an approximate average.

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L5640: (Hexacore; Frequency: 3,4Ghz; Cache: 12MB L3; Threads: 12)

Runtime per WU on Win7 (15-WU average): 1,976h
Granted credit per WU on Win7 (15-WU average): 43,83

Credits per hour (per thread): 22,18
Credits per hour (CPU total): 266,17
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Runtime per WU on Ubuntu 10.04 (30-WU average): 1,227h
Granted credit per WU on Ubuntu 10.04 (30-WU average): 22,82

Credits per hour (per thread): 18,6
Credits per hour (CPU total): 223,18

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Core i7 980X: (Hexacore; Frequency: 3,68Ghz; Cache: 12MB L3; Threads: 12)

Runtime per WU on Win7 (30-WU average): 1,876h
Claimed credit per WU on Win7 (30-WU average): 52,61
Granted credit per WU on Win7 (30-WU average): 42,82
Claimed vs. granted ratio on Win7 (30-WU average): 81,4%

Granted credits per hour (per thread): 22,83
Granted credits per hour (CPU total): 273,9
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Runtime per WU on Ubuntu 10.04 (30-WU average): 1,072h
Claimed credit per WU on Ubuntu 10.04 (30-WU average): 30,71
Granted credit per WU on Ubuntu 10.04 (30-WU average): 22,55
Claimed vs. granted ratio on Ubuntu 10.04 (30-WU average): 73,4%

Credits per hour (per thread): 21,04
Credits per hour (CPU total): 252,43

So... what have we here.
From the looks of it, the Linux client is definitely more efficient. It completes the WUs a lot faster. However, the Windows client gets higher granted credit.
Now the real question is whether Linux and Windows client are getting the exact same work units.

Either way, I'm a little disappointed. I had hoped to present to everyone the "better" OS for crunching, yet it seems people have to choose between getting more science done (if the WUs are the same) or getting higher PPD.

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To better illustrate my findings; I attached a graph. Higher is better except for runtime (which I multiplied by 20 to better show the difference in the chart)

I just can say that I tested the same thing with my X6 @3,6GHz and my results match with yours.

I really would like to know now, if the WUs are the same. If yes, the WCG/BOINC Credit systems would be total crap.

The BOINC inter-project credit system IS total crap.
Have a look at my sig... I got those 16 million on MW with a single HD5870 in a month or so. Huge point differences between projects have always been the case, and will always be the case I guess.

However, if the discrepancies are within WCG, they can (and should) do something about it.
I posted the question whether the WUs are the same over at WCG forums: https://secure.worldcommunitygrid.or...e,yes#lastpost

Let's see what they say.

Let's for a moment assume they are the same amount of work.

The credit is based on what the benchmark score is and how long the unit takes, with a "fudge factor" possibly but more of less that's it. If a Linux box is chewing through the equivalent amount of work in less time due to being more efficient, but has the same or close to the same benchmark scores, then it will logically claim less points per unit. If the benchmark scores are lower for Linux (which I suspect might be the case as the Windows compilers are more efficient for those processes) then it will also claim less points per hour. (That could be verified one way or the other if you have benchmarks for the same version client on both Win7 and Linux). I'd suggest that the credit per hour would be the metric to make the call on as it takes more factors into account and no matter how good the code is on any system, time is close enough to a constant pace. The difference in claimed v granted credit has me intrigued though. It's enough to swing things either way depending on what's causing the variation.

The credit systems on any project are, pretty much, crap anyway. At best they're only an educated guess of what the work is worth on an "average" system. At worst ...

Quote:

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Originally Posted by D_A

Let's for a moment assume they are the same amount of work.

The credit is based on what the benchmark score is and how long the unit takes, with a "fudge factor" possibly but more of less that's it.
If a Linux box is chewing through the equivalent amount of work in less time due to being more efficient, but has the same or close to the same benchmark scores, then it will logically claim less points per unit. If the benchmark scores are lower for Linux (which I suspect might be the case as the Windows compilers are more efficient for those processes) then it will also claim less points per hour. (That could be verified one way or the other if you have benchmarks for the same version client on both Win7 and Linux). I'd suggest that the credit per hour would be the metric to make the call on as it takes more factors into account and no matter how good the code is on any system, time is close enough to a constant pace. The difference in claimed v granted credit has me intrigued though. It's enough to swing things either way depending on what's causing the variation.

The credit systems on any project are, pretty much, crap anyway. At best they're only an educated guess of what the work is worth on an "average" system. At worst ...

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That makes sense.. benchmark score * runtime = score.
Interestingly enough, Windows doesn't score higher on the Benchmark, at least not overall. I just ran it on both machines, here's what I got:

L5640:

Ubuntu 2913/11816 FPU/Integer
Win 7 3123/10085 FPU Integer

980X:

Ubuntu 3184/12899 FPU/Integer
Win 7 3346/10776 FPU Integer

BOINC 6.10.45 on both Windows installs, BOINC 6.10.17 on both Linux installs

Quote:

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Runtime per WU on Win7 (15-WU average): 1,976h
Runtime per WU on Ubuntu 10.04 (30-WU average): 1,227h

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these are some great findings,
if the WU's are the same,

moving!

They seem to be the same, but I am still waiting for a definitive confirmation on that.

Quote:

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They seem to be the same

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how can you tell?
size?

E:
i think the code should be the same, only maybe a different file format,
after all the language should be universal and compilers -faster or slower- are just doing the translation job.

just wondering if they have different servers for both operating systems, and each WU, is going through an automated translation process,
they both should come from the same source,
could be that it's only changing the file format.

Well.. I can't tell for sure, as I keep saying.
But.. everyone on the WCG forums seems to say/think that the WUs are identical.. WU names certainly are identical. Ram usage is about the same as well (~30MB per thread) so it stands to reason that the work packages are, indeed, the same for any type of OS.

Edit: I am seeing a strange phenomenon on both Linux machines. The system monitor doesn't show 100% load on all cores.. there's always at least one core not fully loaded. Now, I have disabled any thermal management in bios so it can't be the CPU throttling. Any idea what else it could be?

That's really weird, jcool. Certainly does look like the CPU throttling itself. Swaps from thread to thread constantly with never any more than 11/12 load.

You sure your preferences in BOINC aren't being overriden to use <100% cores?

BTW

Quote:

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Originally Posted by jcool

Core i7 980X: (Hexacore; Frequency: 3,68Ghz; Cache: 12MB L3; Threads: 12)

[Win7]Granted credits per hour (CPU total): 273,9
[Ubuntu]Credits per hour (CPU total): 252,43

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252.43*(1+[1/12])= 273.4658333333333

Coincidence? :D

Quote:

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Originally Posted by artemm

That's really weird, jcool. Certainly does look like the CPU throttling itself. Swaps from thread to thread constantly with never any more than 11/12 load.

You sure your preferences in BOINC aren't being overriden to use <100% cores?

BTW



252.43*(1+[1/12])= 273.4658333333333

Coincidence? :D

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That pic was of the L5640. And yes I am sure, settings are right, Thermal throttling disabled in bios, temps are ok.

Here's a shot of the 980X, equally weird :rolleyes:
But that system is on a nearly-full 4GB USB stick and is really slow to respond, so maybe it's the USB stick's fault (at least on the 980X rig).

Your better off switching to the server kernel in Ubuntu. You can go to synaptic in the admin menu, and search for kernel-server as I recall. The Desktop and Server kernel's are optimized differently, and the Server tends to be much better at maintaining full load.

Hey vein,

how about you join me in IRC and give me a noob-proof explanation on how to do that? :wasntme:

Does it have 12 active tasks? That'll help determine if it's a BOINC problem or a computer problem.
Are the advanced preferences all OK to run 100% and 12 cores?

If you're going to run the server kernel for 'nix then you need to run Server 2008 R2 as well.

Presently, you're comparing two "Desktop" class OS installs.

I got it stabilised at 100% on the L5640 (no idea how.. didn't change anything).
The 980X still jumps around - I'll put the blame on the slow-as-crap USB stick though. Since we tried lots of stuff including a switch to the server kernel.
And it's definitely nothing trivial, I triple-checked BOINC settings and bios (besides, it runs fine on Win7 with the same Bios settings).

Oh well, the 980X is for a customer anyway, I was just testing it. The L5640 is mine, and stays on Linux for now.

Quote:

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I got it stabilised at 100% on the L5640 (no idea how.. didn't change anything).

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maybe a background process taking priority...

Maybe. Anyway, some news. Uplinger posted the following on the WCG forums:

Quote:

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Originally Posted by Uplinger

HCC does not send out the same exact work unit to both windows and linux. It is as Randzo says, when the first work unit in the quorum is picked up, the OS is set for the wingman. This means linux compares with linux. Windows compares with windows....

A batch consists of about 1500 work units, these work units are split between all the OS's, so there is no discrimination based on batch level.

-Uplinger

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Don't know what to make of that really.. So they are the same, and yet they aren't?

as i said,
the work is being divided (by uplinger at the link) to all OS's from the same batch, they simply are not the same in the sense that each work is different,

the batch doesn't tell the difference between OS's,
a cruncher gets a WU so his partners are getting it only if they use the same OS.

they can't tell how many WU's would go to Linux users and how many would go to Windows,
the batch is simply a collective.
that's maybe the most reasonable solution.

as for Windows vs Linux optimization,
Linux is faster and it is quite known,
they can't optimize they're code (at least not as well) to make Windows client work faster as linux does, as it works different from the Linux client,
it's not about they're code,
it's about the OS.

To me it sounds like all of the WUs come from the same "pool" i.e. the same work gets done no matter the OS. Then that pool gets split up between operating systems and the results are compared from the same OS.
At least it makes sense to me.

To me, the fact that Linux is free is the biggest advantage. The cost of an OEM version of Windows can buy another power supply. While Windows can also be "free," that is either violation of copyright, which is bad, or there might be limits to the number of copies you can have activated. I've had pretty good uptime on 7, but every time I've used Linux, it seems to stay up forever. Unless I :banana::banana::banana::banana: with it, ofc.
I'm not trying to take from what you guys are doing, I just think that in the long run it comes down to personal preferences.

I think what that means is that there's a big pool of WUs and they could go to either Windows or linux crunchers. When one is assigned to a computer, the OS family of that machine will be used for the quorum. So, they're the same in that they're all interchangeable and assigned to OS's at random, but unique in that you'll never see the same WU on both Windows and linux.

shame we just can't confirm it with the developers http://forums.anandtech.com/images/s...miliar/meh.png.

Well... here's roughly a full day (12 CPU days) on the L5640 on HCC - Windows gets more credits, Linux does more work.
Line format is date - CPU time - granted credit - finished WUs (in case anyone is unfamiliar with it)

Win:
25.05.10 0:012:05:23:41 44,190 131

Linux:
27.05.10 0:012:12:12:21 38,221 251

And the 980X:

Win:
24.05.10 0:012:00:36:55 47,408 114

Linux (couldn't find a full 12 day entry yet):
28.05.10 0:011:01:43:40 37,226 242

What are the clockspeeds of these badass chips?

Pretty low, due to crap stock cooling and hot weather... see post 1 (3,68Ghz for the 980X, 3,4Ghz for the L5640).
Normal would be >4ghz on the 980X and 3,8 on the L5640

how do you OC these dualies (X5680) Jcool?

Not at all, if those idiots at German customs keep drooling over my evga SR-2 :shakes:
Now can we stay on topic, please? I know it's hard :D :wasntme:
I'd like to keep this thread easy-to-read for once, so people can gather all the relevant data quickly.

Quote:

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12-Cores: Dual Westmere-EP X5680 (SR-2 missing...) @ 4.3

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hhrm...
dual MB?

then we can go on topic ;).

Am I misunderstanding yor results jcool? I was wondering since you found that wondows was getting higher credit, but the linux system was finishing faster. So in the end do you thing the linux system finishing WU's faster would ever catch up, equal out, or pass the actual credit of the windows maching over time?

I am just not sure i'm quite understanding all the little nuances at work between the 2 systems maby.

Cheers, Mike.

In short: It seems that under Linux, you can compute an identically structured Work Unit (=equally important piece of science) in about half the time it takes to compute an equally big WU under Windows.
In other words, Linux processes Help Conquer Cancer WUs twice as fast as Windows does.
The different credits awarded are due to Linux clients comparing only with other Linux clients, while Windows compares only with Windows. The vast majority of users are running Windows, hence the higher claimed/granted credit (at least that's what we assume). Even though technically Linux should score way better than Windows for granted credit, IF the credit system was fair and IF my findings are correct.

sometimes, it is so easy, just to answer a simple question and raise a smile on a person face and a gratitude in his heart,
what is it with people that they decide just to ignore?
is it nice?
does they like when people do it to them?
do they think of the person involved?
sometimes it is so easy, just to be humble and kind :).

Quote:

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Originally Posted by onex

sometimes, it is so easy, just to answer a simple question and raise a smile on a person face and a gratitude in his heart,
what is it with people that they decide just to ignore?
is it nice?
does they like when people do it to them?
do they think of the person involved?
sometimes it is so easy, just to be humble and kind :).

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Sometimes, just sometimes people actually manage to FIND and USE the forum's very own search function. ;)

http://www.xtremesystems.org/forums/...ight=evga+SR-2

:shakes:
jcool, jcool,
it's not about the SR board..:shakes:.
never mind though :).

Can the difference in points, perhaps also be explained by using different boinc versions?
(6.10.45 in Windows vs 6.10.17 in Ubuntu)

I did already noticed that in Windows boinc 6.10.43 was claiming (and granted) more points than 6.10.18.

I don't use linux (or ubuntu), so i don't know if it would be easy to upgrade to latest stable version of boinc 6.10.56 and then compare windows vs linux using the same boinc version.

Quote:

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Originally Posted by jcool

The vast majority of users are running Windows, hence the higher claimed/granted credit (at least that's what we assume).

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I can kind of follow that line of thought, but why should it make a difference for the claimed credit? Shouldnt that be based on the benchmark score and computing time alone? It used to be like that anyway. I remember some crazy benchmarks in Linux a couple of years ago, maybe thats why they are puishing Linux point wise now.

It could be because Linux machines tend to get the work done faster but on the whole benchmark lower because they're handling server duties etc as well. Less time * lower benchmark (in operation) = lower scores.

If they're doing server tasks..

Jcool, did you grab benchmarks for the machine between OS's?

Well yes, that's a point. Though I suspect that most Linux machines (over the whole grid) aren't dedicated crunchers.

Quote:

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Originally Posted by D_A

It could be because Linux machines tend to get the work done faster but on the whole benchmark lower because they're handling server duties etc as well. Less time * lower benchmark (in operation) = lower scores.

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Quote:

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Originally Posted by STEvil

If they're doing server tasks..

Jcool, did you grab benchmarks for the machine between OS's?

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Did you guys see this post ?

Linux doesn't score lower overall @ BOINC benchmark, on the contrary.

@pfm3136: It's possible, but I don't think so. Plus I've heard people saying BOINC 6.10.17 on Linux gets rather good scores.

Here's another thought: Maybe I (we) get lower credit on Linux, because most Unix machines are non-overclocked, non-dedicated crunchers (ie servers and stuff). Image stock systems being loaded to 30-40% on average with stuff other than BOINC, compared to 100% dedicated and highly OCed machines. A stock i7 920 that has other stuff to handle as well, vs. a dedicated i7 at close to 4Ghz doing nothing but BOINC.

My guess is that there are more people running overclocked machines on Windows; maybe team XS members even get teamed up with other team XS members (= almost all overclocked machines), netting a better score :shrug:

Quote:

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Originally Posted by jcool

Linux doesn't score lower overall @ BOINC benchmark, on the contrary.

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That's weird, I get 3220/9859 in win7 x64, and 3034/16981 in an Ubuntu 10.04 VM (because I can't be bothered to reboot). It scores higher again if I boot the OS properly. Ie, linux absolutely destroys windows at Integer performance on a Q6600. Perhaps this has something to do with the time taken to complete the work units?

I think its just poor scoring methods.

well, they did it for security reasons. there are other ways to do secure wu's. f@h has their wu's encrypted.

Quote:

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Originally Posted by joshd

That's weird, I get 3220/9859 in win7 x64, and 3034/16981 in an Ubuntu 10.04 VM (because I can't be bothered to reboot). It scores higher again if I boot the OS properly. Ie, linux absolutely destroys windows at Integer performance on a Q6600. Perhaps this has something to do with the time taken to complete the work units?

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Jcool's benchmark did show a difference in integer speed (a little less fpu, but more integer performance), but nothing like almost doubling integer performance.
Maybe Kentsfield cpu get more performance benefit from linux than westemere.

It would seem that HCC uses more the integer part of the cpu, and thats may lead to crunch the work unit in almost half the time.

So it seems that i'm going to have to learn how to install and use ubuntu in my Q6600, it's almost a dedicated cruncher, so it will be a install and forget.
Not really worried about the points, as i'm going to mount another pc very soon, just a few more parts needed.

Quote:

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Originally Posted by jcool

Here's another thought: Maybe I (we) get lower credit on Linux, because most Unix machines are non-overclocked, non-dedicated crunchers (ie servers and stuff). Image stock systems being loaded to 30-40% on average with stuff other than BOINC, compared to 100% dedicated and highly OCed machines. A stock i7 920 that has other stuff to handle as well, vs. a dedicated i7 at close to 4Ghz doing nothing but BOINC.

My guess is that there are more people running overclocked machines on Windows; maybe team XS members even get teamed up with other team XS members (= almost all overclocked machines), netting a better score :shrug:

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Here's some more data for you guys to chew on.

This is an unscientific comparison between two very similar machines using the first page of valid results for FAAH.

Credit was granted based on 1 machine (no wingman) except for the last one in each list.
Both run 64-bit versions.
Both are overclocked to 4.0GHz.
Memory speed is 1603MHz.
Win7 is P6X58D Premium.
Win7 benchmarks: 3631/11470
Win7 is my main PC used for browsing, email, etc. and nothing really heavy-duty.
Fedora is P6X58D-E.
Fedora benchmarks: 3386/12638
Fedora is dedicated cruncher.

Code:

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Machine                Time  Claimed        Granted %ofClmd        Points/Hr
Win7-980X        4.20  124.30        105.10        84.55%        25.02
Win7-980X        3.69  109.70        92.80        84.59%        25.15
Win7-980X        3.88  114.90        96.30        83.81%        24.82
Win7-980X        3.63  106.30        87.80        82.60%        24.19
Win7-980X        3.69  108.70        85.60        78.75%        23.20
Win7-980X        2.76    81.60        64.20        78.68%        23.26
Win7-980X        3.64  109.50        84.90        77.53%        23.32
Win7-980X        3.62  108.30        112.20        103.60%        30.99
Win7-980X        3.57  106.10        100.10        94.34%        28.04
Win7-980X        3.48  100.30        83.10        82.85%        23.88
Win7-980X        5.73  168.50        167.50        99.41%        29.23
Win7-980X        4.46  131.40        106.80        81.28%        23.95
Average                3.86  114.13        98.87        86.00%        25.42
                                       
Fedora-980X        3.89  109.80        86.60        78.87%        22.26
Fedora-980X        3.91  101.40        91.20        89.94%        23.32
Fedora-980X        3.41    91.30        73.70        80.72%        21.61
Fedora-980X        3.70    99.80        81.10        81.26%        21.92
Fedora-980X        3.38    90.00        77.50        86.11%        22.93
Fedora-980X        3.44    91.70        78.20        85.28%        22.73
Fedora-980X        3.41    92.50        77.00        83.24%        22.58
Fedora-980X        3.33    89.50        75.60        84.47%        22.70
Fedora-980X        3.38    90.80        85.80        94.49%        25.38
Fedora-980X        4.73  125.10        104.60        83.61%        22.11
Fedora-980X        3.52    97.80        78.30        80.06%        22.24
Fedora-980X        3.55  104.00        77.30        74.33%        21.77
Fedora-980X        3.25    91.70        77.70        84.73%        23.91
Fedora-980X        3.68  103.60        83.80        80.89%        22.77
Fedora-980X        4.06  114.10        87.40        76.60%        21.53
Average                3.62    99.22        82.03        82.92%        22.72

Difference        0.24    14.92        16.84        3.08%        2.71

Percentage        6.30%    13.07%        17.03%        3.58%        10.64%
Difference

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Based on this, fedora did the tasks 6.3% faster, claimed 13.07% fewer points, received 17.03% fewer points, and ended up with 10.64% fewer points/hr.

Who says the point system isn't perfect?:shrug:

I'm not at home right now, but I did a 14 day test between 2 identical computers with the same exact BIOS settings, and using WIndows 7 x64 Ultimate and Ubuntu 10.4. I came up with numbers pretty close to other posters. That is, Linux does more work but benchmarks a lower value and therefore receives less points based on the way WCG calculates points. It's complete BS that LInux can do more work but get less PPD. Their system is broke.

Here's my devil's advocate comment: We're all spending money on computer parts and electricity to do this work. We have proven that their system for calculating points isn't entirely accurate, but we're supposed to trust that the results that we are all providing and paying for (via electricity, heat, and computer parts) actually provide accurate scientific data?

If I went into my previous posts I asked for any comments that they data WCG is using is actually scientifically valid and being used around the world for great studies. I can read lots of posts from people linking to WCG's pages and a study or two using WCG data, but I am beginning to have serious doubts as to how useful this project REALLY is.

I switched from folding at home to WCG about 2 months ago, and I'm starting to having second thoughts on my decision, which is quite disappointing. I'm starting to question the validity of this project and how useful it really is to mankind. Stay tuned because I've decided that I want to do some deep level research on the net and figure out WTH is really going on and if these work units really are as useful as we all have been told.

WCG is supposed to be looking at reworking the points system, but the science always takes priority. Which to me, is completely understandable. Even after reworking it, there is no guarantee that it will ever be perfect.
While the points are a fun way to keep track of the crunching, it is not why I do it.
<rant>In some respects the points are bogus anyway, especially for overall BOINC points. I mean what's the point of having 20 5890s blasting away at endless, useless calculations figuring out if Collatz was right or not? So someone can say they have the most BOINC points or highest BOINC PPD or used the most KWH last month?</rant>

Quote:

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Originally Posted by pirogue

<rant>I mean what's the point of having 20 5890s blasting away at endless, useless calculations figuring out if Collatz was right or not?</rant>

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To figure out if Collatz was right or not. :)

Quote:

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Originally Posted by jcool

Linux doesn't score lower overall @ BOINC benchmark, on the contrary.

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It scores lower at fpu, higher at integer.. Could it be that points are mostly based on the fpu part of the benchmark?
That would explain less points and more work done at the same time, as it seems that hcc can really use well the better integer performance of linux.

Quote:

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Originally Posted by jcool

Here's another thought: Maybe I (we) get lower credit on Linux, because most Unix machines are non-overclocked, non-dedicated crunchers (ie servers and stuff). Image stock systems being loaded to 30-40% on average with stuff other than BOINC, compared to 100% dedicated and highly OCed machines. A stock i7 920 that has other stuff to handle as well, vs. a dedicated i7 at close to 4Ghz doing nothing but BOINC.

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This could explain the granted credit, but not the claimed credit, i think...

Quote:

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I'm not at home right now, but I did a 14 day test between 2 identical computers with the same exact BIOS settings, and using WIndows 7 x64 Ultimate and Ubuntu 10.4. I came up with numbers pretty close to other posters. That is, Linux does more work but benchmarks a lower value and therefore receives less points based on the way WCG calculates points. It's complete BS that LInux can do more work but get less PPD. Their system is broke.

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so what you say actually, is that if one cpu does the same work faster then a second cpu, it would get less points,
they seem to grant more credit per time crunched and not per work done..
E: or either pfm is right.

that is confusing.

can't it be actually tested, i.e - a 980 going 4GHz should be granted less credit then a 980 going 3GHz :hm:?

Quote:

---

Originally Posted by onex

so what you say actually, is that if one cpu does the same work faster then a second cpu, it would get less points,
they seem to grant more credit per time crunched and not per work done..
E: or either pfm is right.

that is confusing.

---

I think the points system is actually a mix (or better, a mess), and it does take runtime into account.
The problem is when the computer is doing something else, it'll take more time to complete the work unit, and so will claim more credit, hence some of the measures they have taken towards the granted credit.

The problems with the points system, is that it isn't very fair, and the benchmark in boinc seems to change a little from version to version.

There isn't a way to test the exact same work unit on linux and windows, but (for example) when someone in linux does 2 wu in 2 hours and 1 wu in windows in the same 2 hours, it doesn't seem very fair that they give more credit for the windows system than the linux one... Unless they are giving credits because of windows price...

Quote:

---

Originally Posted by pirogue

<rant>In some respects the points are bogus anyway, especially for overall BOINC points. I mean what's the point of having 20 5890s blasting away at endless, useless calculations figuring out if Collatz was right or not? So someone can say they have the most BOINC points or highest BOINC PPD or used the most KWH last month?</rant>

---

Because those mathematic problem can be the msissing part in calculation for physic or chemical and by solving those mathematical problem you can solve also alot of other science problem. Thats why i am running collatz and i will be running Edges@home, yoyo@homes and ufluids. Because yes finding a cure for disease is very nice but as a young man with alot of interest in science, i want to help them to figure out how and why everything is happening. Thats why i am not just running wcg and gpugrid but they still use most of my computer ressource.

it can be said that linux would be granted less credit due to less dedicated systems, yet it is also claiming less credit even though it is working faster...

ohh,
found this:

Quote:

---

claimed credit = ([whetstone]+[dhrystone]) * wu_cpu_time_in_sec / 1728000

---

http://www.boinc-wiki.info/Claimed_Credit

Quote:

---

Originally Posted by onex

so what you say actually, is that if one cpu does the same work faster then a second cpu, it would get less points,
they seem to grant more credit per time crunched and not per work done..
E: or either pfm is right.

that is confusing.

can't it be actually tested, i.e - a 980 going 4GHz should be granted less credit then a 980 going 3GHz :hm:?

---

Wow, I just read my previous post and I should have had my morning coffee before posting!

When I compared the 2, the linux machine appears slower on the WCG benchmarks than the windows machine(slightly, something like 5-10% when the benchmarks are run several times to obtain average values).

However, the Linux machine appears to be able to complete work units faster than on Windows 7 x64 Ultimate. The linux machine also generates about 15% less PPD than a windows machine.

Obviously the benchmark numbers have a large effect on the PPD, but I would have expected that Linux would have ultimately been more efficient and so, regardless of the benchmark values, would have produced more PPD.

I would like to note that my test was to determine the maximum PPD, not necessarily the most work units performed.

Overall, my little test concluded that Linux should have provided more PPD, but did not. I came to this conclusion because I figured that since linux appears to have a 5-10% benchmark penalty compared to windows linux would get 5-10% less work completed and would get 5-10% less PPD. Instead, linux appears to do up to 30% more work than windows, but get about 35% less PPD.

Just using Jcool's numbers on L5640:

Credit per hour per thread Win7: 22.18
Credit per hour per thread Linux: 18.6

Runtime per WU on Win7: 1.976 hours
Runtime per WU on Linux: 1.227 hours

Based on those numbers it seems logical to say that the Linux benchmark doesn't do justice when it comes to the horsepower of the processor.

There's alot of variability as to how WCG gives us the PPD value, so it could be that I'm out to lunch on estimating the WCG, or WCG somehow puts Linux at a disadvantage. I'm sure this affect isn't deliberate.

I don't know if I still have my numbers at home. I looked at all of my numbers and after looking at the conflicts I had originally dismissed my data as garbage because I thought I had clearly been making some bad assumptions. Maybe I wasn't too far off.

What would interest me though, a comparison of Windows 7 x64 Ultimate to Home Premium x64. Surely Ultimate has more overhead, so perhaps running Home Premium x64 would be better? Also, a comparison of Windows 7 x64 Ultimate to Windows 7 Starter might be interesting. I know that x64 gives more PPD, but maybe the starter edition has so much less overhead it makes it superior in PPD. Without numbers I don't want to rely on that hypothesis.

I don't know how many of you remember some of the threads/comments I had made about WCG back before I made the switch from F@H, but this is why I asked those questions. There were no numbers, just people saying that this was how it was. I don't like hearing "this is how it is". I like to see numbers or something proving beyond someone's opinion that this really is true. :). I'm an Engineer, and my job is not about providing opinions, it's about providing numbers and facts to support it.

Great work to everyone that has done this research. I'm sure more is to follow and maybe we can figure out what is really going on in terms of PPD.

-Josh

Quote:

---

Originally Posted by onex

it can be said that linux would be granted less credit due to less dedicated systems, yet it is also claiming less credit even though it is working faster...

ohh,
found this:

http://www.boinc-wiki.info/Claimed_Credit

---

Based on the benchmarks seen, that formula would indicate that the linux system should claim more credit for the same runtime (without getting into account the number of work units done), yet, that doesn't seem to happen...

Quote:

---

Originally Posted by pirogue

Here's some more data for you guys to chew on.

This is an unscientific comparison between two very similar machines using the first page of valid results for FAAH.

Credit was granted based on 1 machine (no wingman) except for the last one in each list.
Both run 64-bit versions.
Both are overclocked to 4.0GHz.
Memory speed is 1603MHz.
Win7 is P6X58D Premium.
Win7 benchmarks: 3631/11470
Win7 is my main PC used for browsing, email, etc. and nothing really heavy-duty.
Fedora is P6X58D-E.
Fedora benchmarks: 3386/12638
Fedora is dedicated cruncher.
[snip]
...
Who says the point system isn't perfect?:shrug:

---

What project is that? From the looks of it, not HCC. ONLY HCC is that much faster-running on Linux.. there's maybe a 10-15% difference on the other projects (according to some people over at WCG forums, I have only tested HCC so far).

Quote:

---

Originally Posted by pfm3136

It scores lower at fpu, higher at integer.. Could it be that points are mostly based on the fpu part of the benchmark?
That would explain less points and more work done at the same time, as it seems that hcc can really use well the better integer performance of linux.

This could explain the granted credit, but not the claimed credit, i think...

---

Quote:

---

Originally Posted by onex

ohh,
found this:

http://www.boinc-wiki.info/Claimed_Credit

---

If they are indeed using that formula then both scores seem equally important. Meaning Linux should score better overall with its higher Integer Score.

BOINC benchmarks are slowed by HT, so if I'd disable HT, I'd get higher scores. I might try to re-run the BOINC bench with HT turned off (even though changing active threads usually :banana::banana::banana::banana:s up the program...)

Quote:

---

it can be said that linux would be granted less credit due to less dedicated systems, yet it is also claiming less credit even though it is working faster...

ohh,
found this:
Quote:
claimed credit = ([whetstone]+[dhrystone]) * wu_cpu_time_in_sec / 1728000
http://www.boinc-wiki.info/Claimed_Credit

---

That is a claimed credit calculation though, not granted credit from WCG. I've been looking trying to determine how WCG calculates granted credit and cannot find much. Does anyone know how WCG calculates the granted credit? Has anyone compared the claimed credit scores between Linux and windows(not granted)?

I, unfortunately, have not run any similar/identical systems on both OS's for any significant amount of time so I don't have any data to compare with. I suspect though, according to the BOINC claimed credit calculation, that on the average Linux crunchers will CLAIM more when compared to Windows crunchers. When comparing the GRANTED credits though, it would be less since so far it seems linux machines are awarded less.

-EDIT- I found an article on how granted credit is calculated, still reading it.

Quote:

---

Originally Posted by jcool

What project is that? From the looks of it, not HCC. ONLY HCC is that much faster-running on Linux.. there's maybe a 10-15% difference on the other projects (according to some people over at WCG forums, I have only tested HCC so far).

---

Quote:

---

Originally Posted by pirogue

This is an unscientific comparison between two very similar machines using the first page of valid results for FAAH.

---

FightAIDS@Home

I used it for the example because the granted credit doesn't depend on any other machines (usually).


Edit: :slap: I was focused on Linux vs Windows and completely missed the HCC part of the thread title. At least it's not a problem specific to HCC. I'll shut up now unless someone asks me a specific question.

Doh.. right. Must have overlooked that part of the sentence...
Good to know the PPD between Windows and Linux are equal there though.

First, I made an error earlier. I believe on average that linux machines would claim less credit per result returned based on the claimed credit calculation if they are spending less CPU time per WU. They should also return more work per day on average if they are completing WU's faster. Therefore it should come out in the wash essentially.

According to the WCG wiki the credit system works as follows...

http://wcg.wikia.com/wiki/Credit_system

Quote:

---

The way that credit is awarded in a quorum of two is that the two claimed credits are compared and if they are within 30% of each other, then they are averaged and the average value is granted. Over 85% of workunits have the granted credit determined this way.

If the two claimed credit values are further then 30% apart, then the code looks at a field in the database which stores the recent average credit granted per second for each computer. Whichever computer's claimed credit per second for the workunit is closer to their recent average credit granted per second has its claimed credit used as the credit granted for the workunit.

---

So based on all this, per WU linux machines should be granted less credit. They should, however, be completing more work/day since they take less time to complete the work. Earlier someone mentioned that there may be some linux servers which crunch, but only part time. Perhaps this is skewing the granted credit for people crunching dedicated machines on linux?

Also, while reading through some of this information... it seems like we could "predict" BOINC ppd using the standard credit calculation.

Code:

---

(([whetstone]+[dhrystone])*86400/1728000)*[number of threads]

---

Where 86400 is the total # of seconds during the day. Ive checked it against all my crunchers and in most cases it is close. my quad socket is way off though.

-EDIT- Just realized this thread is supposed to be centered around HCC, sorry!

Actually there's a note in here about the claimed credit:

Quote:

---

Note: There is an additional refinement in that the Project can determine and specify the ratio of Floating Point to Integer mathmatics with a fraction that is used to scale the benchmark multipliers, with the variable "a" representing the scaling fraction, gives us:

claimed credit = ( a * whetstone + (1 - a) * dhrystone) * wu_cpu_time_in_sec / 1728000

---

So it might not be as straightforward as initially thought.
It depends on the real formula used for the WCG project, which might focus more on fpu performance and that might explain linux asking for less claimed credit for the same runtime.
If someone could find the real formula used for WCG project maybe that could shed a little more light on this matter.


Nonetheless and in spite of what might be found about points, already burned ubuntu to a cd, and will change my Q6600 to it next weekend, as it'll get more work done for the same time.
If we can accelerate and cut the time in half for finishing a project, why not?

Ahh, I didn't see that. Well, I'll keep looking around and if I find anything useful I'll post it.

Quote:

---

Overall, my little test concluded that Linux should have provided more PPD, but did not. I came to this conclusion because I figured that since linux appears to have a 5-10% benchmark penalty compared to windows linux would get 5-10% less work completed and would get 5-10% less PPD. Instead, linux appears to do up to 30% more work than windows, but get about 35% less PPD.

---

the issue with linux getting less credit is probably due to the approximate difference between the dhrystone+whetstone vs CPU_time per WU_in seconds,
i.e, if linux get an higher whetstone+dhrystone sum, it might come above the difference in seconds when dividing with 1728000,
- when looking closer at pirogue results (last page), the whetstone+dhrystone sum, is 6.39% more for linux and so the avg calculation time, is ~6.22, (add difference between WU's and it comes out ~ the same).
i.e - if a WU is going for 4 hours at windows (14,400 sec) and 6.3% less in linux (13,464 sec) and the whetstone+dhrystone sum, is too 6.3%, 15001 vs 16024,
then,
Windows, goes, (15001*14400) / 1728000 = 125.008
Linux, goes, (16024*13464) / 1728000 = 124.85...

so, what we can see, here, is that there is a difference, even though it is slight, which means, that even though Linux is a faster cruncher, it can claim less points,
as for the granted points, it is possible indeed, that most heavy crunchers are using windows, at OC'ed systems and 24/7.!

E: pfm, just seen your post,
then this might explain the differences, up and down between projects and inaccuracies of the original formula.

now,
have a look here:

Quote:

---

Points are calculated in a two-step process which attempts to give a consistent number of points for similar amounts of research computation. First, the computational power/speed of the computer is determined by periodically running a benchmark calculation. Then, based on the central processing unit (CPU) time spent computing the research result for a work unit, the benchmark result is used to convert the time spent on a work unit into points. This adjusts the point value so that a slow computer or a fast computer would produce about the same number of points for calculating the research result for the same work unit. This value is the number of point credits "claimed" by the client.

---

https://secure.worldcommunitygrid.or...ame=points#177
quite communistic, isn't it..?
yet, at a second thought,
if they did it by the CPU power, then a slower CPU, would have gotten a lousy result, claiming for only few points, and the faster CPU, would have gotten a high result,
then the granted credit between the two, would have pushed up significantly the slower CPU and pull down significantly the faster CPU.
this is not so good for future compatibility as well, as processors get faster and more advanced and others stay slow, this would harm they're efforts even further, comparing to older CPU's.
the basic advantage of using a faster CPU, then, is not coming from it's ability to process any WU faster, rather from it's ability to process more WU's per day,
that's it's actual benefit.

Quote:

---

That is a claimed credit calculation though, not granted credit from WCG.

---

what we care, is for claimed credit, because granted does not represent anything we can work with,
granted goes by comparing the claimed credit for a WU per it's crunching participants, and taking some average,
that is why people have said that Linux could be suffering from lack of OCed machines and dedicated crunchers in comparison to windows, which is much more popular, and even more with casual users.

Quote:

---

-EDIT- Just realized this thread is supposed to be centered around HCC, sorry!

---

p.s - guys, it seems to be o.k, flowing with different projects, other wise it would be difficult for everyone to compare results while not using HCC specifically,
as long as it contribute to the thread and Jcool doesn't mind it in particular, go on with it.

Feel free to compare Linux and Windows on other projects as well.. we've already established that Linux is faster in HCC in post 1.

I think a point weight on the WU based on expected completion time should be used. Longer they are expected to take, the more points they are worth.

That way benchmark numbers dont matter, actual work performed does.

The benchmark is, in theory at least, important because it gives an impression of the work potential of a given machine. Hence the work potential and the actual time spent should be very good factors in determining what a machine's expended effort is.

The other alternative is to make all work units worth a fixed amount of credit, based on their completion times of a single, standardised machine (which is how Folding@Hades operates, from memory). That has the advantage of being "fair", in that a work unit is worth x no matter what machine or OS does the work. The trick (and I'd bet some substantial arguments) comes in determining what the "standard" machine is.

edit: Disclosure - Yes I realise that if all HCC work units were worth the same point value regardless of time, Linux machines would SLAUGHTER Windows machines (AT THE MOMENT. That could change with the next application release, who knows.)

Forgive me for being a conspiracy theorist, but I've been pondering this all afternoon. Believe me, i am not a conspiracy theorist generally. I just don't see how Linux could be as fast as it appears, yet still have less PPD than Windows.

Is it at all possible that Microsoft is somehow involved in the reason why Windows gives more points than Linux despite all of the information provided. I did look at the WCG "partners" and Microsoft is not directly listed, but Microsoft has been known to be involved via other subsidiaries. There's 426 partners listed on WCG, so I'm not sure we'd be able to identify if Microsoft is a partner at all. If Microsoft was involved in this, I wouldn't be too surprised. It definitely won't be the first time that MS has been caught being involved in projects solely to make their products look better than their competition.

Truth be told, if people were building lots of machines just to fold (and gee, nobody does that here, right?) alot of people would be buying extra copies of Windows, wouldn't they? That's ALOT of money if you think about it, so Microsoft does stand to lose some easy money off of those that build a farm of computers to crunch if Linux were used instead of Windows...

I want to reiterate that this is ALL open for conjecture, I have ZERO proof of this, just a hypothesis.

Quote:

---

Originally Posted by onex

what we care, is for claimed credit, because granted does not represent anything we can work with,
granted goes by comparing the claimed credit for a WU per it's crunching participants, and taking some average,
that is why people have said that Linux could be suffering from lack of OCed machines and dedicated crunchers in comparison to windows, which is much more popular, and even more with casual users

---

I brought it up because both linux machines I run take heavy hits on the granted credit VS claimed on a couple projects. Sometimes it will grant me down to 18% of the claimed credit, so initially I suspected that somehow linux was hit harder pointwise by these projects for some reason I cannot determine. I don't seem to have this similar problem with windows.

What it boils down to is I thought perhaps something in the calculation to figure out Granted credit vs claimed credit was suspect. And since the granted credit is what actually gets reflected in WCG point totals, it seems to me that BOINC claimed credit is worthless if the granted credit is going to cut the score down by 82%.

Quote:

---

Originally Posted by D_A

The benchmark is, in theory at least, important because it gives an impression of the work potential of a given machine. Hence the work potential and the actual time spent should be very good factors in determining what a machine's expended effort is.

The other alternative is to make all work units worth a fixed amount of credit, based on their completion times of a single, standardised machine (which is how Folding@Hades operates, from memory). That has the advantage of being "fair", in that a work unit is worth x no matter what machine or OS does the work. The trick (and I'd bet some substantial arguments) comes in determining what the "standard" machine is.

edit: Disclosure - Yes I realise that if all HCC work units were worth the same point value regardless of time, Linux machines would SLAUGHTER Windows machines (AT THE MOMENT. That could change with the next application release, who knows.)

---

Basing the credit per WU on a single machine would be worse than what we've got now.

2 hours WU: 2 points
2.5 hour WU: 2.5 points
3 hour WU: 3 points...

If you finish the 3 hour WU in 2 hours, you get 3 points..

Quote:

---

Originally Posted by STEvil

Basing the credit per WU on a single machine would be worse than what we've got now.

2 hours WU: 2 points
2.5 hour WU: 2.5 points
3 hour WU: 3 points...

If you finish the 3 hour WU in 2 hours, you get 3 points..

---

Yeah, you'd get 3 points, but you'd get it in two hours instead of three. If you're machine is 50% faster than the standard then you'd be getting 50% more credit. How exactly is that worse than what we have now?

i think that method sounds better...

Quote:

---

Originally Posted by Someguy1982

I brought it up because both linux machines I run take heavy hits on the granted credit VS claimed on a couple projects. Sometimes it will grant me down to 18% of the claimed credit, so initially I suspected that somehow linux was hit harder pointwise by these projects for some reason I cannot determine. I don't seem to have this similar problem with windows.

---

Well, i do have the same problem as you in most of the work units, and i'm using Windows, not all the wu, but most, it seems to depend too much on the wingman.
As for FAAH, which doesn't use a wingman normally, sometimes it's seems an obscene robbery of points.

Also, if you check the statistics for the different projects within WCG you might note that theres a huge difference in points per hour between some of them.

Quote:

---

Originally Posted by D_A

Yeah, you'd get 3 points, but you'd get it in two hours instead of three. If you're machine is 50% faster than the standard then you'd be getting 50% more credit. How exactly is that worse than what we have now?

---

Yep, i also think it would be more just/fair.

Quote:

---

Windows, goes, (15001*14400) / 1728000 = 125.008
Linux, goes, (16024*13464) / 1728000 = 124.85...

so, what we can see, here, is that there is a difference, even though it is slight, which means, that even though Linux is a faster cruncher, it can claim less points,

---

actually, this is not true,
as low of commutativity says, ([D]+[W])*WU_sec / 1728000, will equal if we take 6% of both of the parameters,
the sum, should be the same.
even though D+W numbers through windows sums higher then linux, they perform the task in less proportional time and so, the multiplication in the formula gives ~the same result,
i.e, as said in the pointing scheme explanation, - a faster processor should get the same points as a slower processor-.
maybe they do the comparison between the WU's PPD, in order to cancel any chance of people changing they're results..

Quote:

---

The benchmark is, in theory at least, important because it gives an impression of the work potential of a given machine.

---

it is said, that they bench the machine every now and then to take measurements of it's current performance.

Quote:

---

The other alternative is to make all work units worth a fixed amount of credit, based on their completion times of a single, standardised machine (which is how Folding@Hades operates, from memory). That has the advantage of being "fair", in that a work unit is worth x no matter what machine or OS does the work. The trick (and I'd bet some substantial arguments) comes in determining what the "standard" machine is.

---

sounds like a good alternative.

Quote:

---

What it boils down to is I thought perhaps something in the calculation to figure out Granted credit vs claimed credit was suspect. And since the granted credit is what actually gets reflected in WCG point totals, it seems to me that BOINC claimed credit is worthless if the granted credit is going to cut the score down by 82%.

---

yeah,
you lose a decent portion of your CPU potential.
maybe it has something to do with linux,
yet, this pointing scheme do create some problems,
by the original formula, 2 CPU's should give ~the same results, yet actually, what happens, is one is taking the other up or down.
as an add,
it is not the points that are really important, yet they give the user a good estimate of it's work, it is like watching a benchmark.

Josh,
currently, doubt it...

Quote:

---

Originally Posted by D_A

Yeah, you'd get 3 points, but you'd get it in two hours instead of three. If you're machine is 50% faster than the standard then you'd be getting 50% more credit. How exactly is that worse than what we have now?

---

Worse?

Its better. If you do more WU per time used you generate more points. More points drives people to better efficiency.. more efficiency, more work done. Points will be based on work done, not theoretical performance.

Ok, now I'm confused.

The whole point of basing returned credit on how long a "standard" machine takes to do the work unit is completely congruous with what you proposed. The system we have now tries to give credit based on how long the unit takes and the assumption that different machines will take different times to do it. Running a sample unit on a "standard" machine and then concluding that all the units in that batch are worth n points is what I'm suggesting and exactly the same as what you counter proposed. In both cases, a given unit is worth a fixed value. If you throw a more powerful machine at it and do it quicker then you end up doing more units and hence get more PPD. No crazy benchmark formulae, no quorum to decide credit, if it's valid you get n. Period. If you do them faster then you get more ns and get more credit than the machine that only does one a week instead of six hundred a day.

Quote:

---

Running a sample unit on a "standard" machine and then concluding that all the units in that batch are worth n points is what I'm suggesting

---

maybe i'm missing something here, yet,
WCG, is doing some 600K results per day, and it would need 400 batches for that (1500 WU's per batch),
the other thing, is that not all WU's are similar within a batch, so they cannot say, every unit within this specific batch, is worth x points,
they might be able to do an estimate, yet even in the BOINC manager, estimates are changing as the WU is being processed...

Quote:

---

Originally Posted by pfm3136

Well, i do have the same problem as you in most of the work units, and i'm using Windows, not all the wu, but most, it seems to depend too much on the wingman.
As for FAAH, which doesn't use a wingman normally, sometimes it's seems an obscene robbery of points.

Also, if you check the statistics for the different projects within WCG you might note that theres a huge difference in points per hour between some of them.

---

Fair enough, I haven't noticed this problem on the windows machines I run though. At least not as bad as the linux machine. I understand the granted credit is typically not the same as claimed credit. However, when I'm getting 45 credits for something the machine is claiming 240 credits on, that seems extreme and I wonder if something is wrong.

Quote:

---

Originally Posted by onex

yeah,
you lose a decent portion of your CPU potential.
maybe it has something to do with linux,
yet, this pointing scheme do create some problems,
by the original formula, 2 CPU's should give ~the same results, yet actually, what happens, is one is taking the other up or down.
as an add,
it is not the points that are really important, yet they give the user a good estimate of it's work, it is like watching a benchmark.

Josh,
currently, doubt it...

---

Agreed, after reviewing the formula it seems fair and using it should yield the same points given similar hardware. It's not though, and I am at a loss as to why that would be.

Quote:

---

Originally Posted by Someguy1982

Fair enough, I haven't noticed this problem on the windows machines I run though. At least not as bad as the linux machine. I understand the granted credit is typically not the same as claimed credit. However, when I'm getting 45 credits for something the machine is claiming 240 credits on, that seems extreme and I wonder if something is wrong.

---

Like i said, not in all work units, but i've seen up to 30% difference from claimed to granted. It depends a lot on the wingman, i've seen some ask almost half of my claimed credit, and that obviously takes the granted credit down.
But that example really is extreme, it would seem like you have a real high benchmark and they suspect something and cut the credit in half, or more...
I've already seen from 240 to 150, but not to 45, that's too much...


Well, already installed ubuntu in my Q6600, (it doesn't seem to like hdmi cable, had to use a vga cable), it started immediatelly downloading work for HCMD before i could change that pc to the profile for HCC, so i will have to wait a little to see the difference.
On Windows it did the HCC work units in about 1 hour and 40-50 minutes.

Quote:

---

Originally Posted by jcool

In short: It seems that under Linux, you can compute an identically structured Work Unit (=equally important piece of science) in about half the time it takes to compute an equally big WU under Windows.
In other words, Linux processes Help Conquer Cancer WUs twice as fast as Windows does.
The different credits awarded are due to Linux clients comparing only with other Linux clients, while Windows compares only with Windows. The vast majority of users are running Windows, hence the higher claimed/granted credit (at least that's what we assume). Even though technically Linux should score way better than Windows for granted credit, IF the credit system was fair and IF my findings are correct.

---

Awsome! Thanks mate. i'm glad I asked because I was getting things a little twisted here. I always hated having to compare to the other machines WU's that get turned in I guess thats the "Q" factor. I never understood things clearer till now. Cheers.

For now, it's taking between 40-55 minutes per work unit in my Q6600 @ 3200MHz. So that's half the time, maybe a little less than half the time it took in Windows.
Here it seems to be claiming more credit for the same runtime than in Windows.
About 50-55 for Windows and 60+ for Ubuntu for 2 hours runtime (boinc points).
The granted credit depends heavily on the Wingman, so i was getting very low granted credit, but now seems a little better, about the same as claimed.

Just saw the statistics for the first day, did some math, and wow, it seems to really be getting more points. It is claiming more points in ubuntu than it did in Windows, it just sucks to have some wingmans that take double the time and ask half the credit...
I'll have to wait for a least a week to let it average well the numbers and go to the PPD Predictor thread share the results, because my Q6600@3200MHz in Windows 7 x64 was doing 4.8 (WCG points) PPD per MHz, now in Ubuntu, the first day, it did 5.9 PPD per MHz.

so is XP somewhere in between linux and win7 in terms of points and amount of work done?

After a week running on Ubuntu, my average PPD went from 15-16k to 18k wcg PPD.
So, although the difference in claimed vs granted points, i'm getting more points in Ubuntu than i did in Windows7 x64.