Bi-Xeon X5677 or X5680
 

Hi

I'm newbie in searching primes with prime95 and GIMPS.


What do you think is better for hunting 10M/100M digits primes

A workstation with two Intel Xeon X5677 @ 3,46Ghz and 4-core per processor

or

The same workstation with two Xeon X5680 @ 3,33Ghz and 6-core per processor ?

(or simply a 2 workstations with Core i7 980X ?)

and

Do you think is better to assign a number per processor
or
a number per two processor ?


Thanks for reading my text in english :)

Caffreys

More cores are better (assuming the data bandwidth is not an issue.)

Best for 10M range, 1 core per number (these are fast enough to test that throughput is the main issue.)

Best for 100M, 3 or 4 cores per number (these take so long that speed is generally the main issue).
For a 6 core processor 2 numbers on 3 cores each will give a good blend between speed and throughput.

Test out the machine by running at least 2 Double Checks on each core, to start. This should help to show that the machine is stable.

Thanks for advices !

So X5680s are probably better for Prime95

I'm just afraid that 12 10Mdigits-numbers for 2 Xeon X5680 will give a big CPU usage and thermal dissipation.

I've tried to compute 4 10Mdigits-numbers at a time on a Core i7 975 and the cores temperature was near 85°c/185°F this July.

Caffreys

[quote=Caffreys;224365]

I've tried to compute 4 10Mdigits-numbers at a time on a Core i7 975 and the cores temperature was near 85°c/185°F this July.
[/quote]

Ummm.... unless you were overclocking the CPU VERY hard, that means the cooler you´re using is not good enough for the job, or wasn´t properly assembled.
The cooler that comes with the CPU is rather crappy for serious computing tasks; get something else, preferably some Thermaltake or Noctua stuff.

[quote=Caffreys;224303]Hi

I'm newbie in searching primes with prime95 and GIMPS.


What do you think is better for hunting 10M/100M digits primes

A workstation with two Intel Xeon X5677 @ 3,46Ghz and 4-core per processor

or

The same workstation with two Xeon X5680 @ 3,33Ghz and 6-core per processor ?

(or simply a 2 workstations with Core i7 980X ?)

and

Do you think is better to assign a number per processor
or
a number per two processor ?


Thanks for reading my text in english :)

Caffreys[/quote]

Just for 10M numbers cheaper (and more) dual or quad hardware is more effective. For the hunt for 100M the 980x got the most bang (check out the 100M hardware benchmark thread). The Xeons are fine but you can't overclock them and they give you features which aren't needed for prime hunting.

[quote=joblack;225456]The Xeons are fine but you can't overclock them and they give you features which aren't needed for prime hunting.[/quote]
...such as ECC, and who in the right mind needs it anyway? :razz:

ECC is supported by the X58 (workstation) chipset: [url]http://www.intel.com/Assets/PDF/datasheet/320838.pdf[/url] (page 161ff.)

And what chips do they put in the [I]workstation[/I] class? See intel's site.

[URL="http://ark.intel.com/Compare.aspx?ids=39718,41313,37147,41447,47933,47932"]Also[/URL]...

Next person willing to do a 100M number may want a W3530 Xeon, at least, or better. And then a bit of patience. [URL="http://mersenneforum.org/showthread.php?p=221134#post221134"]Or else[/URL].

[QUOTE=joblack;225456]The Xeons are fine but you can't overclock them and they give you features which aren't needed for prime hunting.[/QUOTE]This is not true : I saw some Asus motherboards (other manufacturers should have them as well) that accept i7 and Xeon processors. With such a motherboard you can overclock a Xeon. Some of those processors even have a TurboBoost mode, which is in effect overclocking.

Jacob

[quote=S485122;225642]This is not true : I saw some Asus motherboards (other manufacturers should have them as well) that accept i7 and Xeon processors. With such a motherboard you can overclock a Xeon. Some of those processors even have a TurboBoost mode, which is in effect overclocking.

Jacob[/quote]

That's true but the advantage of Xeon cpus is that you can have more than one cpu (dual cpu system) in a system. Without that option in a normal mainboard they are just expensive 'normal cpus' ...

No doubt Xeons are the better solution (especially if you want to have full ECC support) but that costs you much more. I was focusing more on the performance vs. price relationship.

By the way, the Turbo Mode is only 'effective overclocking' if you have single or dual core applications. If you want to use Prime95 that's really not an advantage. I disable turbo mode by default - the cores are running all the time anyway ;).

[quote=Batalov;225625]And what chips do they put in the [I]workstation[/I] class? See intel's site.

[URL="http://ark.intel.com/Compare.aspx?ids=39718,41313,37147,41447,47933,47932"]Also[/URL]...

Next person willing to do a 100M number may want a W3530 Xeon, at least, or better. And then a bit of patience. [URL="http://mersenneforum.org/showthread.php?p=221134#post221134"]Or else[/URL].[/quote]

I don't think overclocking is generally not advised. It can be a problem if you go to high and want to have the maximum out of it. Just try the maximum overclocking and go down by 2% - 4% ...

[quote=joblack;225943]That's true but the advantage of Xeon cpus is that you can have more than one cpu (dual cpu system) in a system. Without that option in a normal mainboard they are just expensive 'normal cpus' ...

No doubt Xeons are the better solution (especially if you want to have full ECC support) but that costs you much more. I was focusing more on the performance vs. price relationship.
[/quote]
No, not much more. The price difference recently all but disappeared - that's why I mentioned it.

Here's a toy system:
[URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16819117243"]W3530[/URL] instead of a [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16819115225"]i7 930[/URL] is extra $25 -- $315
[URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16820139040"]ECC 12Gb[/URL] of memory (because one may want to do an occasional Block Lanczos or something else) - $308
[URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16813131357"]Workstation board[/URL] is just a bit more expensive than the desktop enthusiastic boards - $280

All these components bears a mere markup of ~ +10%, not a +100%.

[quote=Batalov;225953]No, not much more. The price difference recently all but disappeared - that's why I mentioned it.

Here's a toy system:
[URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16819117243"]W3530[/URL] instead of a [URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16819115225"]i7 930[/URL] is extra $25 -- $315
[URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16820139040"]ECC 12Gb[/URL] of memory (because one may want to do an occasional Block Lanczos or something else) - $308
[URL="http://www.newegg.com/Product/Product.aspx?Item=N82E16813131357"]Workstation board[/URL] is just a bit more expensive than the desktop enthusiastic boards - $280

All these components bears a mere markup of ~ +10%, not a +100%.[/quote]

At first you don't need 12 GByte of memory (that's the main reason you get a moderate percentage price increase). The i730 is overpriced as hyperthreading is contraproductive for Prime95 usage (as shown in the i790x benchmark). Use an i760 instead. The workstation mainboards are around 120 USD.

With this configuration in mind you'll get more than a 10% price increase.

Anyway, you will always find a way to tweak the configuration so that a Xeon will or won't look expensive.