how to build a FEA workstation? (hardware questions) 2

[coteesh]

I'm going to custom build a FEA workstation.
I called up an ANSYS reseller, and they gave me the general mumbo jumbo "you need lots of RAM, buy the fastest CPU, fastest hard drives, and fastest everything".... bla bla bla. I have a budget here, in fact, the budget is about $1400 USD for the workstation + monitor! This is actually quite resonable, from my experience because I purchased a workstation 9 months ago with 1 gig of RAM at this price and it nicely runs pretty big FEA problems. Computers have become cheaper since then though, so I can get something faster now.

I want more detailed information than what the ANSYS boys gave me, that they couldn't provide on the phone. I have two computer workstations that I have priced out and I need to make a decision between them (cost/performance decision). Assume that I am going to run medium sized problems (with number of elements less than 200,000 tetrahedral, lets say).

System 1:
Athlon 2400+
nForce2 based mother board with Dual-channel DDR 333
1x 80 gig hard drive


System 2:
P4 2.53 Ghz
Motherboard also has Dual-channel DDR ram, but from Tomshardware guide (

http://www.tomshardware.com)

the motherboard has ****70% faster RAM bandwidth***
2x 80 gig Maxtor hard drives in type 0 RAID array.


The System 2 costs $300 more than the System 1. Both systems have similar CPU and FPU speeds. However, the RAM bandwidth is a big concern to me.... how much faster can I solve FEA problems with 70% faster physical RAM bandwidth?

Also, how much will the RAID hard drives help in terms of FEA speed? I believe the type 0 RAID allows for 2x the speed of a typical IDE hard drive, total bandwidth getting close to around 60 megs/sec. with 2.

I need to know if the extra $300 should be spent on this new System 2, or should I simply get rid of the RAID, get rid of the faster RAM, and upgrade the CPU to a 3 GHz for the $300 ???? (depends on your answer to previous questions)

These are the questions I have. Thanks!

 

[GSC]

Hi, its hard to give a fair advice, because Ansys is a package which needs everything, fast CPU, fast RAM and fast HDD. Pretty large files are written to the HDD, CPU-RAM communication is frequent and the FPU has to work hard too. I have seen systems like the 2nd running and the performance is impressive.

If I would be you...
Go for the highest CPU (FSB) speed you can afford, but matching the RAM speed to the CPU is very important, so go for that dual channel DDR (1gig should be enough for the problem size you mentioned). I assume you know how to set RAM speeds accordingly if the bios goes for the safe side.
RAID won't help if the CPU and RAM can not catch up...
ah, 1 more thing... I am (still) an Intel fan

hopes this helps...

 

[coteesh]

Thank you this is perfect! Just the info I wanted. Thanks! I will likely go for system 2, and consider upgrading the CPU.

 

[blc22]

From what I have seen ANSYS does not formally support the AMD processors only Intel processors and a few others are supported. That doesn't mean ANSYS won't run on your new computer it just means that you may have problems with technical support.

 

[coteesh]

Right, I phoned them and that's what they said to me. Likely they wouldn't even bother to support it. However, I have run Ansys on an Athlon system - AMD Athlon XP 2100+ on an ABIT KX7-333 motherboard and 1 gig DDR-333 and MSI GeForce 3 Ti500 64 meg card with no problems, it never crashed after maybe 100 hours of use. I'm probably going to stick with system 2 though, for the primary reason that the motherboard I found for the P4 has both RAID and the 70% faster RAM, I had difficulty finding any Athlon system that had the same RAM bandwidth as Intel, and at the same time with RAID 0.

I'm a little dissapointed that few high-end software vendors support AMD, it would be nice to have a little more competition in the corporate world and drive Intel prices down more. Athlon systems seem to be primary used by home users and gamers. The price of Athlon is very attractive. Though it seems my final choice will be Intel.. thanks for the tips guys.