Testing / comparing : Intel D975XBX2 / Asus P5B DX ***56K WARNING***

[hotchoc]

Thanks guys, since I am using a MCW30 on my NB I decided to use my MCX159-CU on the SB. A little twist to break the TIM loose and it came off o-k.

is the swiftech fan noisy ? am thinking of getting it as well

[LiteBeer]

GTJ
Great Guide

[SiGfever]

is the swiftech fan noisy ? am thinking of getting it as well

No, not at all, I have been very pleased with this cooler.

[Blacklash]

Wonder if Penryn will work in the BX2.

[hotchoc]

OK i started back at 333X9 all at stock levels.

Let's say i were to increase the FSB to say 340 and it fails, most likely i will be increasing the vcore. Let's say that it fails as well, will i be increasing the vFSB or vMCH ?

How do you know which one to increase? vFSB, Vcore or VMCH? You have to juggle with 3 probabilities here.

Left my memory at 266:533 (1:1) and vdimm at 2.0V to underclock it and to focus more on the CPU first. Is this correct?

[gtj]

OK i started back at 333X9 all at stock levels.

Let's say i were to increase the FSB to say 340 and it fails, most likely i will be increasing the vcore. Let's say that it fails as well, will i be increasing the vFSB or vMCH ?

How do you know which one to increase? vFSB, Vcore or VMCH? You have to juggle with 3 probabilities here.

Left my memory at 266:533 (1:1) and vdimm at 2.0V to underclock it and to focus more on the CPU first. Is this correct?

At this point you may want to just increase all 3 and get it to work. Then you can start lowering each and see where it breaks again. Go up to 1.4 Vfsb, 1.6 Vmch and 1.5 Vcore and see what happens.

[gtj]

Wonder if Penryn will work in the BX2.

I would think "yes" with a BIOS update but I guess we won't know until Intel makes more info available.

[chaotic646]

Awesome work on the guide gtj. I'll be printing it when you have it completed.

[Speederlander]

If I run a RAID card on the 3rd PCI-e, does that drop the first PCI-e to x8 electrical?

[argylesocks]

A 1:1 FSB to Memory ratio sounds nice but the critical comparison is FSB throughput to real-world memory throughput. Ideally, you want the 2 to be close.

can you expand on this a bit, gtj?

the whole "1:1 ratio" was drilled into my head as the "best" when i started here... but a few brave souls said they thought a 2:3 or 4:5 gives better results...

care to shed some more light?

fyi: im running a 4:5 ratio now, and dont really notice a difference either way.

[minsc_tdp]

Well I think I've screwed up my RAM. The system is now Orthos Blend unstable (bombs immediately) after approximately 8-12 hours of idle operation. I come home and my VMWare is spewing errors and the system is generally wonky. The VMWare instance at 128 MB RAM is new so it could be an issue but the problem seems hardware related.

I've gradually reduced my volts and clocks to near stock. All stock on the CPU, the mem is around 2.2 or 2.3V. Everything in my gut says the RAM is unstable. It's not the CPU clocks so now I'll need to start over and gradually work them back up again. The problem is somewhat more severe with high CPU clocks (380+) but it doesn't really have much of an effect vs. 266 MHz. So it's clearly the RAM.

The G.skill site says 2.2-2.4V. When I started it was OK at 1.8V and I quickly got it up to 2.2V. I eventually got to 2.4V and it's not helping this problem. How much further should I push it? I feel like it's a wild goose chase though. I also noticed after pushing the ram to 2.4V that a quick jump down to 2.2V was not bootable, it had to rest for a while. It seems most comfortable around 2.38V but right now it's just never stable.

I think I should start the RAM at the current 2.38V and beat on it with memtest for a minimum of 18 hours and try increasing the volts again if it is unstable, maybe going past 2.4 even though it's not even overclocked. I'd like to find a quicker way to determine that the memory is bad (maybe OCCT?), it's very odd that the system has to sit idle for 8 hours before the problem kicks in.

[gtj]

If I run a RAID card on the 3rd PCI-e, does that drop the first PCI-e to x8 electrical?

No. The first 2 PCI-e slots are hung directly off the MCH and do share the same 16 lanes. The 3rd is electrical x4 and is hung off the ICH.

[gtj]

can you expand on this a bit, gtj?

the whole "1:1 ratio" was drilled into my head as the "best" when i started here... but a few brave souls said they thought a 2:3 or 4:5 gives better results...

care to shed some more light?

fyi: im running a 4:5 ratio now, and dont really notice a difference either way.

I may have been one of those who said 1:1 is the best but after doing the math and running benchmarks, I've changed my mind and may have to apologize for making statements without evidence to back them up.

1:1 sounds nice. The FSB and memory are running at the same clock speeds so that must be the most efficient, right? All other things being equal, maybe 1:1 is more efficient that 4:5 but the reality is somewhat different.

The fact is that any "efficiency" the MCH may see is vastly overwhelmed by another fact.... Data passing between the processor and memory is limited by the SLOWEST link. If your FSB is running at 8 GB/s and your memory bus is running at 6 GB/s, then data can only pass between the processor and memory at 6 GB/s. PERIOD. If moving your ratio from 1:1 to 4:5 brings the memory bus to 7 GB/s that's a 17% increase. Gee, so it may not be as efficient as 1:1. Who Cares? Honestly, I can't even find any documentation to support that there was any efficiency loss in the first place.

This is easy to test. Set your FSB to a value that let's you run 1:1 plus either 2/3 or 4/5 reliably. Run an Everest Cache and Mmeory benchmark at 1:1, then without changing anything else, set a 2/3 or 4/5 and run the benchmarks again. Throughput should go up and latency should go down. What a concept.

[ChaosMinionX]

I may have been one of those who said 1:1 is the best but after doing the math and running benchmarks, I've changed my mind and may have to apologize for making statements without evidence to back them up.

1:1 sounds nice. The FSB and memory are running at the same clock speeds so that must be the most efficient, right? All other things being equal, maybe 1:1 is more efficient that 4:5 but the reality is somewhat different.

The fact is that any "efficiency" the MCH may see is vastly overwhelmed by another fact.... Data passing between the processor and memory is limited by the SLOWEST link. If your FSB is running at 8 GB/s and your memory bus is running at 6 GB/s, then data can only pass between the processor and memory at 6 GB/s. PERIOD. If moving your ratio from 1:1 to 4:5 brings the memory bus to 7 GB/s that's a 17% increase. Gee, so it may not be as efficient as 1:1. Who Cares? Honestly, I can't even find any documentation to support that there was any efficiency loss in the first place.

This is easy to test. Set your FSB to a value that let's you run 1:1 plus either 2/3 or 4/5 reliably. Run an Everest Cache and Mmeory benchmark at 1:1, then without changing anything else, set a 2/3 or 4/5 and run the benchmarks again. Throughput should go up and latency should go down. What a concept.

Setting say FSB to 400... Then running 266ref and mem at 533 gives you DDR2 800 1:1 but if you set 667 it gives you ddr2 1000 4:5 and if you keep the same timings and FSB of course its going to be faster and have lower latency you changed the memory frequency to 500 instead of 400. Or am I reading what you said wrong?

[chaotic646]

Ive been experimenting with ratios again as well. Now that its getting hot outside, I decided to switch to my "summer overclock" so I dropped my fsb to run my e6600 @ 3.0 instead of my max 3.4. Running at 3.0 actually underclocked my memory lower than the maximum recommended 400Mhz with a 1:1 ratio, so I moved up to ref 266 and mem at 667. Now my memory is a 4:5 ratio, running at 417 MHz and completely stable. I havent done any benchmarks, but I would assume that since my memory is mildly overclocked now instead of underclocked my system should run a little faster. Or I could be totally wrong.

[gtj]

Setting say FSB to 400... Then running 266ref and mem at 533 gives you DDR2 800 1:1 but if you set 667 it gives you ddr2 1000 4:5 and if you keep the same timings and FSB of course its going to be faster and have lower latency you changed the memory frequency to 500 instead of 400. Or am I reading what you said wrong?

Exactly.
At 400 MHz, your FSB thoughput is 12.8 GB/s.
At 1:1 your memory throughput is 6400 MB/s.
At 4:5 your memory throughput is 8000 MB/s.

It's simple math. 8000 is better than 6400.

[Forceman]

This is easy to test. Set your FSB to a value that let's you run 1:1 plus either 2/3 or 4/5 reliably. Run an Everest Cache and Mmeory benchmark at 1:1, then without changing anything else, set a 2/3 or 4/5 and run the benchmarks again. Throughput should go up and latency should go down. What a concept.

If anyone decides to test this, go ahead and run some other tests as well to see what kind of benefit this has in the real world. Maybe some game benchmarks or SuperPi (actually, that's probably not memory intensive) - anyway something to verify that it is better to run asynch.

[ChaosMinionX]

Exactly.
At 400 MHz, your FSB thoughput is 12.8 GB/s.
At 1:1 your memory throughput is 6400 MB/s.
At 4:5 your memory throughput is 8000 MB/s.

It's simple math. 8000 is better than 6400.

Yes, but of course running a higher memory is going to be faster regardless of 1:1 or 4:5, but 400fsb 1:1 DDR2 800mhz on 533 is going to run faster than say 319fsb 4:5 DDR2 800mhz on 667 mem frequency.

So Its not necessarily an ideal comparison just that your memory is being overclocked by doing so, so of course it would be faster. Or am I interpreting your statement wrong gtj?


EDIT: However to Contribute to your statement regarding bandwidth..... heres a quick bench I did.

FSB: 400mhz / ref freq. 266 / mem ref 533 DDR2 800 1:1 3-3-3-6

--------[ EVEREST Ultimate Edition 2007 (c) 2003-2007 Lavalys, Inc. ]---------------------------------------------------

Version EVEREST v3.80.951 Beta
Benchmark Module 2.1.184.0
Homepage http://www.lavalys.com/
Report Type Quick Report
Computer DEUSEXMACHINA
Generator AjaX
Operating System Microsoft Windows XP Professional 5.1.2600 (WinXP Retail)
Date 2007-04-03
Time 23:28


--------[ Memory Read ]-------------------------------------------------------------------------------------------------

Xeon 3060 3600 MHz Intel Bad Axe 2 D975XBX2 i975X Dual DDR2-800 3-3-3-6 9917 MB/s
--------[ Memory Write ]------------------------------------------------------------------------------------------------

Xeon 3060 3600 MHz Intel Bad Axe 2 D975XBX2 i975X Dual DDR2-800 3-3-3-6 7270 MB/s
--------[ Memory Copy ]-------------------------------------------------------------------------------------------------

Xeon 3060 3600 MHz Intel Bad Axe 2 D975XBX2 i975X Dual DDR2-800 3-3-3-6 7210 MB/s
--------[ Memory Latency ]----------------------------------------------------------------------------------------------

Xeon 3060 3600 MHz Intel Bad Axe 2 D975XBX2 i975X Dual DDR2-800 3-3-3-6 43.5 ns



FSB: 400mhz / ref freq 266 / mem ref 667 DDR2 1000 4:5 4-4-4-12

--------[ EVEREST Ultimate Edition 2007 (c) 2003-2007 Lavalys, Inc. ]---------------------------------------------------

Version EVEREST v3.80.951 Beta
Benchmark Module 2.1.184.0
Homepage http://www.lavalys.com/
Report Type Quick Report
Computer DEUSEXMACHINA
Generator AjaX
Operating System Microsoft Windows XP Professional 5.1.2600 (WinXP Retail)
Date 2007-04-03
Time 23:32


--------[ Memory Read ]-------------------------------------------------------------------------------------------------

Xeon 3060 3600 MHz Intel Bad Axe 2 D975XBX2 i975X Dual DDR2-1000 4-4-4-12 10014 MB/s
--------[ Memory Write ]------------------------------------------------------------------------------------------------

Xeon 3060 3600 MHz Intel Bad Axe 2 D975XBX2 i975X Dual DDR2-1000 4-4-4-12 7293 MB/s
--------[ Memory Copy ]-------------------------------------------------------------------------------------------------

Xeon 3060 3600 MHz Intel Bad Axe 2 D975XBX2 i975X Dual DDR2-1000 4-4-4-12 7749 MB/s
--------[ Memory Latency ]----------------------------------------------------------------------------------------------

Xeon 3060 3600 MHz Intel Bad Axe 2 D975XBX2 i975X Dual DDR2-1000 4-4-4-12 44.0 ns


For me DDR800 3-3-3-6 is rock solid on orthos for 24hrs+, with 2.32v
DDR2 1000 wont even boot cas 3 with anything around that voltage, so I went with the usual 4-4-4-12 and thats what I came up with marginal increases if at all between using either 1:1 or 4:5 however the timings of my DDR2 800 is very very tight for 24/7 thats why I paid for the domc3's but if you dont I suppose 4-4-4-12 DDR2 800 would get pounded by DDR2 1000. So I will go ahead and agree with Gtj on his statement

[gtj]

Yes, but of course running a higher memory is going to be faster regardless of 1:1 or 4:5, but 400fsb 1:1 DDR2 800mhz on 533 is going to run faster than say 319fsb 4:5 DDR2 800mhz on 667 mem frequency.

So Its not necessarily an ideal comparison just that your memory is being overclocked by doing so, so of course it would be faster. Or am I interpreting your statement wrong gtj?

Well, I just tested the the 2 scenarios you describe and 400,1:1 did run slightly faster memory throughput than 319,4:5 but I think it's more to do with the processor running at 3.6 GHz instead of 2.88 GHz

Also, in order to do a valid test, you have to run the memory in single channel mode (1 stick) otherwise the effects of running both channels skews the results.

So I will go ahead and agree with Gtj on his statement

[/QUOTE]

Gee thanks.

[ChaosMinionX]

Well, I just tested the the 2 scenarios you describe and 400,1:1 did run slightly faster memory throughput than 319,4:5 but I think it's more to do with the processor running at 3.6 GHz instead of 2.88 GHz

Also, in order to do a valid test, you have to run the memory in single channel mode (1 stick) otherwise the effects of running both channels skews the results.




Gee thanks.

Aye, while only seeing a valid performance increase on Memory Copy, however had I checked the same timings I know the 3-3-3-6 DDR2 1000 would have destroyed the DDR2 800, but its to be expected running same speed tighter timings whether its synchronous or asynchronous

None the less still very constructive

[hotchoc]

Guys,

I keep failing my orthos tests usually at the 30 mins mark after going past the 333FSB mark. What does it mean ? What's the difference of failing an orthos test at say 1-2 mins and failing in 2-3 hrs later?

My stable settings are vcore 1.325 @ 333FSB. vMCH and vFSB are in default levels and ram timings are 5-5-5-15 @ 1:1. To reach 335 FSB, i require a vcore of 1.3375. Orthos fails at around 30-40 mins mark if i were to up the FSB to 336,337,338,339,340. The question here is why an increase of the vcore only nets a small FSB which in my case is only an increase of 3 FSB !!! O_O

[ChaosMinionX]

Guys,

I keep failing my orthos tests usually at the 30 mins mark after going past the 333FSB mark. What does it mean ? What's the difference of failing an orthos test at say 1-2 mins and failing in 2-3 hrs later?

My stable settings are vcore 1.325 @ 333FSB. vMCH and vFSB are in default levels and ram timings are 5-5-5-15 @ 1:1. To reach 335 FSB, i require a vcore of 1.3375. Orthos fails at around 30-40 mins mark if i were to up the FSB to 336,337,338,339,340. The question here is why an increase of the vcore only nets a small FSB which in my case is only an increase of 3 FSB !!! O_O

set vMCH to 1.6v vFSB to 1.4v and then try booting 400x9 1.4v or 350+ 1.375-1.5v is a good range to stay in with quality air cooling or water.

And make sure your Ref Freq is 266, and mem freq is 533 so it stays 1:1 and wont hit DDR2 800 till 400fsb. Tune it from there, or what kind of OC are you looking for?

[minsc_tdp]

Well I think I've screwed up my RAM. The system is now Orthos Blend unstable (bombs immediately) after approximately 8-12 hours of idle operation. I come home and my VMWare is spewing errors and the system is generally wonky. The VMWare instance at 128 MB RAM is new so it could be an issue but the problem seems hardware related.

I've gradually reduced my volts and clocks to near stock. All stock on the CPU, the mem is around 2.2 or 2.3V. Everything in my gut says the RAM is unstable. It's not the CPU clocks so now I'll need to start over and gradually work them back up again. The problem is somewhat more severe with high CPU clocks (380+) but it doesn't really have much of an effect vs. 266 MHz. So it's clearly the RAM.

The G.skill site says 2.2-2.4V. When I started it was OK at 1.8V and I quickly got it up to 2.2V. I eventually got to 2.4V and it's not helping this problem. How much further should I push it? I feel like it's a wild goose chase though. I also noticed after pushing the ram to 2.4V that a quick jump down to 2.2V was not bootable, it had to rest for a while. It seems most comfortable around 2.38V but right now it's just never stable.

I think I should start the RAM at the current 2.38V and beat on it with memtest for a minimum of 18 hours and try increasing the volts again if it is unstable, maybe going past 2.4 even though it's not even overclocked. I'd like to find a quicker way to determine that the memory is bad (maybe OCCT?), it's very odd that the system has to sit idle for 8 hours before the problem kicks in.

Sorry to repeat this but I really need some advice, it's driving me mad...

[hotchoc]

set vMCH to 1.6v vFSB to 1.4v and then try booting 400x9 1.4v or 350+ 1.375-1.5v is a good range to stay in with quality air cooling or water.

And make sure your Ref Freq is 266, and mem freq is 533 so it stays 1:1 and wont hit DDR2 800 till 400fsb. Tune it from there, or what kind of OC are you looking for?

Looking for 400X9 mate. The best i've gone so far is
1.5 Vcore
1.4 vFsb
1.6 vMch
380X 9
Orthos fails in 19 mins though and my XP crashed
Ram ratios are 1:1 @ 266:533

[argylesocks]

Looking for 400X9 mate. The best i've gone so far is
1.5 Vcore
1.4 vFsb
1.6 vMch
380X 9
Orthos fails in 19 mins though and my XP crashed
Ram ratios are 1:1 @ 266:533

maybe, maybe not, but you could be one of the unlucky ones (like me) who will just never reach the 400x9 mark. my voltage needs increased like crazy after 345x9.... i too, was hoping for 3.6ghz.. but it just aint gonna happen for me. wish you luck.

decide what your max voltage that you are comfortable with, set it, and then work your fsb from there... you may be failing at 380x9.. but could be totally stable at 370x9 at that voltage... still a very good OC