Building memory intensive rig on a budget?

[Mad Ad]

Ok, time to de-lurk :) .... I need advice for a new PC to run upto 40 multiple instances of a piece of custom software that sits in memory all its life.

I dont need huge CPU performance (current PC is an M2N with an X2 @2.4 which sits at 30%-40%) and I dont need great graphics performance.

What i do need is the blistering memory > cpu > NIC performance, without breaking the bank. Its in a competitive environment so I really need to nail this one as best I can.

So far my research suggests that I should stick with AMD for its on die memory controller and I was going to get one of the faster X2s (800 memory bus tho), stick it on a AM2+ board with 1066 memory and clock it up to increase the memory bandwidth to nearer the 1066 level. I like Asus boards, probably an M3N but not sure which one again :shrug: .

However Im learning that HT3 might be needed to make the most out of the 1066 memory? (1066 = 17GB/s b/w and 32 bit HT2 bandwidth tops out at 16GB/s bi) but maybe that wont matter that much? I dont know.

I thought I had figured most of this out :cry: but now the low end phenoms (8450) are starting to look attractive price wise and would be a straight fit for the 1066 memory, but also I hear in these forums talk about northbridge frequency.

Please help me out with some suggestions power guys, Ideally i want a board without a southbridge (lower power and more direct route for mem>cpu>nic) and hope that all ive written up there makes sense.

[zanzabar]

intel has more bandwidth amd has lower latency, and are u looking to do it with a minor oc, if so then the 8400 with a 400fsb and a p35/45 is unstoppable while remaining perfectly stable

and some mushkin 1066mhz 996619

[Mad Ad]

wow quick first reply, thanks - ok maybe im getting confused, the software needs the best latency I can get. Speed is everything.

Only 1 or 2 of the 40 processes needs to be quick at any one time, but all of them sit waiting to react to external events, which happen at random times. A bit like a tripswitch- once something changes externally, one of my apps need to react to that as soon as electrically possible, which seems to fit the AMD way of processing?

Overclocking is not necessary, the whole box isnt expected to go over 40% CPU, but I have overclocked every pc I have ever built for myself (and several others), i just cant resist :)

[zanzabar]

overclocking is to lower latency, a core 2 with some fsb from 400-425 is still perfectly stable but vary low lat, if u dont oc then the amd is the way to go and just make sure that ur an amd 790 chipset

[Mad Ad]

why the 790? i hear good words about it but the only Asus 790 (M3A32-MVP Deluxe) has 3 full size pcie, a southbridge, looks hotter than hadies and is way over budget- with tons of stuff on it that ill never use- is it that different to the 8200/750a? What would I give up?

Lot of unhappy bods here on the M3A too http://www.xtremesystems.org/forums/showthread.php?t=171582

Can anyone else shine some light on this please? I just need best latency performance from memory to NIC and to hell with all the rest.

I know most of you guys use your kit for a multitude of things from gaming to rendering, but this is just a single use PC which doesnt need the vast majority of addons PCs have today, and I appreciate the difficulty dropping of out of the 'must have the best of everything' mindset, I do get it too (if it was a multi use PC id be clocking up a E7200) just this is a bit different and I cant afford to spend shedloads of cash on things Ill never use.

[Antinomy]

Well, I think, I can help. If your budget is not big, then you need AMD platform. But what do you need - memory bandwith or lowest latency?
We're having a contest in CIS, and two systems could make 33ns in Everest - that was the AMD s939 system on Winbond memory, running at 1,5-2-2-5 and about 255MHz. The second one was the DDR3 memory running at a high frequency.
If you need a big bandwith two, then get a fast CPU. It's because the AM2 bandwith depends on CPU frequency. 3GHz and higher will be nice. That's normal for Athlon X2 5000+ Black Edition and for the 6000+.
If you won't have a fast CPU, then overclocking the memory by itself from 800 to 1066 will make an effort near to none.

[Mad Ad]

Ok thank you both, learned some things from your post Ant, thanks for that, and made sure I got a 790 too (DFI) so I should be good to go.

Still not sure if im doing the right thing to get best performance for my software, but in the absence of anyone to guide me guess I will have to try and see.

[AbuSom3a]

What software are you exactly using?

[SocketMan]

Wait a few days and grab one of the new 790gx boards that
are coming out next week.I'd go with the dfi one(they'll have 2
actually) 790gx DK+790gx JR. ~120-150 $
You get an option of running 'ganged" or "unganged"
modes with the Phenoms since it actually has 2 IMC which can
work independently (unganged) great for multi threaded applications or together (ganged) - good for single threaded.
The unganged will let you run different modules, with !
different timings(Cas/trp/tras...etc....)
I am sure Intel is on par, just don't have a "recent" Intel rig
to compare but their next gen (Nehalem) looks deadly (will
certainly have better memory performance)

Here is an excellent analysis of ddr2 performance for AMD and
Intel
http://www.digit-life.com/articles3/mainboard/ddr2-yorkfield-phenom-page1.html
It's long;)