Need great floating point number cruncher.

dullard

Elite Member
May 21, 2001
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I'm ashamed to ask after being a long time poster here regarding CPUs. But, I haven't paid attention to CPUs for the last two years. I know absolutely nothing about the recent advances.

I need the fastest possible number crunching capabilities. Software was designed to run optimally on multiple CPUs/multiple cores. But, I'd perfer to have a limit of 2-3 cores running simultaneously so that I can use the software license on another computer at the same time (only 4 licenses).

Is the Xeon or Opteron better now? What do their prices look like compared to just a Core 2 Duo?
Are they all fully 64-bit as I may need access to 4+ GB of memory?
Has Vista gotten its bugs worked out? Or should I use the 64-bit Windows XP? The software that I'll be using is supposed to work on Vista but it hasn't been validated yet. So, I'm mostly interested in user friendlyness of the OS.

What would you get with $3k-$4k?
[*]NVIDIA Quadro® FX 3450 or better is a must.
[*]4+ GB of memory is a must.
[*]Software isn't necessary, other than an OS.
[*]250 GB HD is a must.
So, what is the best processing power I can get with that budget and those components in mind?
 

GuitarDaddy

Lifer
Nov 9, 2004
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If your going with a workstation/server class motherboard and regestered ram, I would say the xeon 3220 quad core 2.4ghz, or the desktop equivalent Q6600 if your going with a normal desktop board and unbuffered ram. They are essentially the same CPU and both sell for around $300. For your needs a quad core is definately the way to go, if you don't want all four cores dedicated to the app, just set the affinity on one of the cores to something else.

At the current time, Intel is definately the performance leader over opterons/X2's

I would choose vista 64bit over XP 64bit, as vista was designed as a 64bit system and ongoing driver support will be better with vista.
 

lopri

Elite Member
Jul 27, 2002
13,314
690
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Normally I wouldn't suggest to play waiting game (you know, the better things are always around the corner), but with the kind of budget you're planning to invest, I'd say wait a bit.

1. Barcelona is supposed to improve FP performance dramatically.
2. Intel has a revised V8 (a la QuadFX) in the wings to debut soon, and it will not require FB-DIMMs.
 

dullard

Elite Member
May 21, 2001
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Ok, I looked around a bit more. Looks like the Q6600 has problems on that software when going from 3 cores (83% efficient) to 4 cores (72% efficient). The thought was limited memory bandwidth.

Two dual 5140 Xeons have a faster FSB, and aren't quite as limited when using all four cores. (No efficiency data, but it looked like it scaled quite well).

Thus, when using all 4 cores, the dual 5140 looks better, but in all other cases, saving $900 with the Q6600 looks better. Since I plan to use only 3 cores, I'll probably go with the Q6600.

Lopri, is the Q6600 going to be getting a FSB increase if I wait?
 

swtethan

Diamond Member
Aug 5, 2005
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you can get 5 PS3's for 3k and load linux onto them + your programs (if they work) :D lol
 

HopJokey

Platinum Member
May 6, 2005
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Originally posted by: dullard
Ok, I looked around a bit more. Looks like the Q6600 has problems on that software when going from 3 cores (83% efficient) to 4 cores (72% efficient). The thought was limited memory bandwidth.

Two dual 5140 Xeons have a faster FSB, and aren't quite as limited when using all four cores. (No efficiency data, but it looked like it scaled quite well).

Thus, when using all 4 cores, the dual 5140 looks better, but in all other cases, saving $900 with the Q6600 looks better. Since I plan to use only 3 cores, I'll probably go with the Q6600.

Lopri, is the Q6600 going to be getting a FSB increase if I wait?

If the FSB is an issue, you could try overclocking the front side bus without overclocking the chip much at all.

For example, you can get the Q6600 which runs at default 9 x 266 FSB = 2.4 Ghz. Overclock the FSB to 333 (1333 effective) and set the multiplier to 8 and you get: 8 x 333 = 2.66Ghz which would not be a problem in terms of heat or stability whatsoever. You can even bump down the multiplier to 7 if you are at all worried about OC'ing (7x333 = 2.33 Ghz).
 

MarcVenice

Moderator Emeritus <br>
Apr 2, 2007
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He isn't going to get an ecc ram and wants to save money. So I guess oc-ing isn't totaly out of the question. An oc-ed q6600 @3ghz will be rocksolid with good cooling. For the money he has he could build 2 rigs :)
 

dullard

Elite Member
May 21, 2001
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It'll be a university computer and thus almost certainly from Dell. I'm not sure if you can even overclock a Dell Precision workstation 390 or 690 (models I've looked at so far today).
 

Markfw

Moderator Emeritus, Elite Member
May 16, 2002
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You haven't mentioned anything about I/O. Do you need a really fast subssytem ? If so, you would want a PCI-X slot, and a SCSI 320 controller, and an array. This would require a server class motherboard. You could get 2 Opteron 290's on a board like that. I think the Opterons@2.8 would be faster than the Q6600@2.4.

If IO isn't important, the X3220 or Q6600 is probably the best way to go. As to the OS, I won't touch the bloated Vista that requires a gig just to boot, but......
 

HopJokey

Platinum Member
May 6, 2005
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Originally posted by: dullard
It'll be a university computer and thus almost certainly from Dell. I'm not sure if you can even overclock a Dell Precision workstation 390 or 690 (models I've looked at so far today).
If this is the case then the choice between 2-way dual core Xeon or 1-way quad core is a more difficult decision. I would still lean toward the q6600 system because it uses less power (and is cheaper).

It would be great if you could take advantage of a 8 core system, because on dell.com I configured a 2-way quad-core Xeon E5345 (2.33Ghz @ 1333 FSB) for $690 more than a comparable 2-way dual core system.
 

HopJokey

Platinum Member
May 6, 2005
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Originally posted by: Markfw900
You haven't mentioned anything about I/O. Do you need a really fast subssytem ? If so, you would want a PCI-X slot, and a SCSI 320 controller, and an array. This would require a server class motherboard. You could get 2 Opteron 290's on a board like that. I think the Opterons@2.8 would be faster than the Q6600@2.4.

If IO isn't important, the X3220 or Q6600 is probably the best way to go. As to the OS, I won't touch the bloated Vista that requires a gig just to boot, but......

Heh I wonder if Linux could be an option? If not then Vista x64 is the only way to go since he wants 4 GB of RAM.
 

dullard

Elite Member
May 21, 2001
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IO to/from the memory to CPU is all that matters. While there is a little disk usage, it isn't a significant part of the picture. I may get one fast drive and one large drive, but I haven't decided yet.

8-cores is out of the price range that the prof. is willing to license. So, I'm stuck with a 4 process license. Dual quad cores would be a waste for me in that case.

Linux is an option. But I have had so little experience with it, that I dislike it. And the performance gains are visible, but not significant.

I found some more benches (using 2 cores in this comparison, higher is better):

OPTERON_2CORE,2200: 3555.6
OPTERON_2CORE,2600: 4114.3
OPTERON_2CORE,2800: 4376.9
IA64_MONTECITO_2CORE,1600: 2452.1
EM64T_WOODCREST_2CORE,2300 4571.4
EM64T_WOODCREST_2CORE,2300: 4937.1
EM64T_WOODCREST_2CORE,3000: 5818.2
EM64T_WOODCREST_2CORE,3000: 5934.1
EM64T_WOODCREST_2CORE,3000: 6362.3

I beleive the differences in the indentical processors is the OS. Linux is maybe a 10% boost. Am I correct that the EM64T_Woodcrest is Xeon? If so, the 2.8 GHz Opteron is basically the same speed as tthe 2.3 GHz Xeon.

GuitarDaddy's Q6600 suggestion appears to be the ideal processor. With it, I may well be under $3k.
 

HopJokey

Platinum Member
May 6, 2005
2,110
0
0
Originally posted by: dullard
IO to/from the memory to CPU is all that matters. While there is a little disk usage, it isn't a significant part of the picture. I may get one fast drive and one large drive, but I haven't decided yet.

8-cores is out of the price range that the prof. is willing to license. So, I'm stuck with a 4 process license. Dual quad cores would be a waste for me in that case.

Linux is an option. But I have had so little experience with it, that I dislike it. And the performance gains are visible, but not significant.

I found some more benches (using 2 cores in this comparison, higher is better):

OPTERON_2CORE,2200: 3555.6
OPTERON_2CORE,2600: 4114.3
OPTERON_2CORE,2800: 4376.9
IA64_MONTECITO_2CORE,1600: 2452.1
EM64T_WOODCREST_2CORE,2300 4571.4
EM64T_WOODCREST_2CORE,2300: 4937.1
EM64T_WOODCREST_2CORE,3000: 5818.2
EM64T_WOODCREST_2CORE,3000: 5934.1
EM64T_WOODCREST_2CORE,3000: 6362.3

I beleive the differences in the indentical processors is the OS. Linux is maybe a 10% boost. Am I correct that the EM64T_Woodcrest is Xeon? If so, the 2.8 GHz Opteron is basically the same speed as tthe 2.3 GHz Xeon.

GuitarDaddy's Q6600 suggestion appears to be the ideal processor. With it, I may well be under $3k.

This is correct; Woodcrest is a Merom-core based Xeon part.