Which CPU??!!

kifi

Having done some research its still up in the air as to what CPU I should choose for my new self build 'puter.
I intend to use it for everyday 'puter tasks but primarily for Finite Element Analysis ( a CAE programme) which involves a lot of number crunching and with 3-D models.
I am willing to pay up to 600 for one.

Any thoughts appreciated.

Cuddlesworth

http://www.komplett.ie/k/ki.asp?sku=309863

SouperComputer

can your software distibute the work amongst networked machines?

If so you will get much more power for your money if you buy some older 2.0ghz machines.

wingnut

At I guess I'd say for that kind of money the high end AMD 64 bit processors. AMD have quad core opterons that I would imagine are best for something like that. Have a look at benchmarks, try somewhere like tom's hardware guide. The superpi benchmark would be useful for something like that.

Inspector Gadget

I suspect that you should have a close look at the packaging for your app. There is some historical precedent for certain high-performance math-heavy applications being compiled in such a way as to optimise them for use on one specific family of processors - for desktop boxes, this is almost always tilted in favour of Intel hardware.

If not, however, and it's just using i386 and SSE/SSE2 instructions, the FPU performance of the high-end A64's will beat the Pentium 4 black and blue, despite a double-pumped ALU in the P4.

You should also check if your application can make use of SMP setups; if it doesn't specifically mention this, you may well be better off going with the fastest single core processor (of whatever preferred pedigree) you can get your mitts on within your price range.

From what I remember, FEM computations will be largely in-memory, so lots of fast RAM may well bring worthwhile benefits to the table.

In other words, if you're building an application-specific machine, check your application's preferred dietary habits before taking the plunge

Hope this helps,
Gadget

kifi

Gadget - The programme I will use is called Abaqus and on their website SMP support is mentioned, http://www.abaqus.com/support/v65/v65_platforms.html.

SouperComputer - The programme can distribute the tasks accross networked machines, however I don't feel that I'm willing to invest in more than one system as this work will only last the next 12 months.

WizZard

wingnut wrote:

AMD have quad core opterons that I would imagine are best for something like that.

Not yet they don't - at least not available to the general public.

SouperComputer

kifi wrote:

SouperComputer - The programme can distribute the tasks accross networked machines, however I don't feel that I'm willing to invest in more than one system as this work will only last the next 12 months.

The point I am making is by distributing the work amongst a series of less powerfull and cheaper machines, you get a LOT more processing power for your money.


Heres an example of the performance of such a setup: http://www.boards.ie/vbulletin/showpost.php?p=51133699&postcount=25

It deals with 3D rendering, but the performance difference is stark.

You could go for a setup with say 4x 2.0Ghz P4's with 256Mb RAM. It would bury the single DC chip and cost about the same as each CPU has its own dedicated cache, memory controller and FSB.

So there is much to be gained from such a setup. For a start, the cache on DC chips is shared.

Do you already have a motherboard for the task? If not have a chat amongst your collegues about such a setup.

here is a thread discussing a similar situation to yours.

http://www.extremetech.com/article2/0,1697,1847518,00.asp
^ another article, a bit old, but still give you an idea of the "bang for your buck" by going with such a setup.

Inspector Gadget

Hmm... FEM should be reasonably easy to parallelise (the fact that the link you provided mentioned both thread and MPI parallelism suggests they expect many users will do just that)

I'd imagine that the biggest bang-for-buck for your money would be a dual-core A64 or Opteron running on Linux (as there doesn't seem to be a 64-bit-native version available for Windows yet); however, you may already have bought the Windows version of this program for all I know. If you do go the Linux route, you'd be getting a statically linked binary, so you'd be strongly advised to check what version of what distro they compiled on to get the thing working smoothly.

SouperComputer's notion of a cluster of cheap machines isn't a half-bad idea; though Gigabit Ethernet is significantly slower than HyperTransport, the difference in price between high-end and middle-of-the-road CPUs is so high that you could probably afford two (or even three) middling to decent PCs which together would give you more raw computing power, and possibly even channel bond two Gigabit NICs together in each machine for better inter-process communications performance.

(Damn, this doesn't take account of the cost of the software licences, does it? )

Gadget

SouperComputer

Im putting my head on the block here, as im not sure exactly how this software works, but GB ethernet will most likely not be needed, as you are not trying to replace the HTB or FSB with it.

Usually for a farm the respective software breaks the work into batches of instructions. Somewhat like a vector, I guess. The likes of folding@home, superpi etc operate in a similar manner. A small amount of data\parameters can have your CPU crunching for a good while.

Just had a quick look at their website, I think some cheapo PC's off the FS board will give you maximum horsepower for little money. Licencing and deployment issues aside..........

Inspector Gadget

Yeah, it does depend on the actual demands of the application. If each computer takes long enough to process every logical piece of the job (basically, how many mesh elements, if I remember correctly), then the network interface won't be saturated; basically, it depends on how the jobs are divided out.

Gadget

kifi

Thanks for all the input guys.

I have gotten my hands on a P4 3.0Ghz for next 12 months so I plan to network this with the pc I am to build. I think Im gonna go with an AMD X2, 2Gb of fast RAM, a nice high res 20" TFT......

kifi

What do ye think of this system from Komplett?

BenQ DVD±RW burner, DW1655, 16x, Dual,
EPoX EP-9NPA+ Ultra, nForce4 Ultra,ATX
AMD Athlon 64 X2 4400+ 2.2GHz Socket
Seagate Barracuda 7200.9 250GB SATA2
Cooler Master Wave Master Black
OCZ Technology Powersupply ATX 450W
Corsair Value S. PC3200 DDR-DIMM 2048MB
PowerColor Radeon X800GT EVO 256MB GDDR3

Comes in at 1395. Anything I should consider changing in this setup? Would there be a noticeable difference going from the 4400+ to the 4600+?

SouperComputer

You should probably find out how sensitve the software is to memory speeds. Possibly consider faster RAM.

Personally, Id throw the graphics card and more RAM if needed in the P4 3.0Ghz system and make a farm with the rest of the money.

Is overclocking a possibility? You can be pretty sure the 4400 will run at 4600 speeds stable, even considering the "mission-critical" type work you have in mind. For the sake of the extra money, id run with the 4400 if you are hell-bent on having a single DC computer.

Would an older Nvidia Quatro card be of benefit to this software, as opposed to the "consumer" ATI and Nvidia range?