[utkunun]

Dear all,

I have two configurations that are affordable with my budget. I would like to have your thoughts on their performance comparison. The running code will preferably be OpenFOAM.

Say we have two cases to run: A and B.

T1: Time elapsed for running A and B consecutively on configuration 1.
T2: Time elapsed for running A and B simultaneously on two separate computers with configuration 2.

Is T1 or T2 is bigger?

Here are the configurations:

Configuration 1:

Dual Intel® Xeon® Processor E5-2650 v4 (12C, 2.2GHz, 2.9GHz Turbo, 2400MHz, 30MB, 105W)
32GB (4x8GB) 2400MHz DDR4 RDIMM ECC
16 DIMM / 1TB
2.5" 256GB SATA SSD + 2 x 1.2TB 2.5" SAS 10000 RPM

Configuration 2:

Dual Intel® Xeon® Processor E5-2630 v4 (10C, 2.2GHz, 3.1GHz Turbo, 2133MHz, 25MB, 85W)
32GB (4x8GB) 2400MHz DDR4 RDIMM ECC
8 DIMM / 256GB
2.5" 256GB SATA SSD + 1TB 3.5" 7200 RPM

As you might have guessed, cost of configuration 1 doubles that of configuration 2.

Thanks in advance,

Utku

[flotus1]

I am not sure If you can really get C2 for half the cost. There are more or less fixed costs for the case, power supply, motherboard, RAM, GPU... the only difference are the CPUs. At least there are some issues I would like to address:
1) Both systems are ill-configured for a CFD workload. You need 8 DIMMs to make use of the quad-channel memory interface of both CPUs.
2) I see no point in those pesky and expensive 10k rpm HDDs for a CFD workstation. They cost nearly as much as SATA SSD and are still much slower. Plus not many CFD workloads are slowed down significantly by a normal HDD. If you are on a budget, use 3.5" HDDs with 7200rpm. I personally consider HDDs with 1TB a waste of space and I/O ports. HDDs with 2 or 3 TB cost much less $/TB.
3) Last not least: with Intels Skylake-SP and AMDs Epyc CPUs just around the corner I would not recommend buying Broadwell-EP unless it is really urgent for whatever reason. You will get much more performance/$ for CFD once they are available.

To answer your question: 2xC2 will outperform C1 by a large margin in your scenario.

[utkunun]

Dear Alex,

Thank you for your helpful response.

Regarding your comments, could you please recommend a modified version of configuration 2 so that it is no longer ill-configured?

These are Dell brand workstations that I received from a local distributor, so that is the price that they tell me.

I will not be able to wait longer for the new processor architectures due to the deadlines I have. But thanks for the information anyway.

Regards,

Utku

[evcelica]

Originally Posted by flotus1

To answer your question: 2xC2 will outperform C1 by a large margin in your scenario.

True dat
Twice the memory bandwidth with 2 computers. You can hook them together with 2 infiniband cards if you want to get into that as well.

[flotus1]

Originally Posted by utkunun

Regarding your comments, could you please recommend a modified version of configuration 2 so that it is no longer ill-configured?

The only thing you really need to change is the memory configuration. You need 8 DIMMs per node. I would recommend 8x8GB dual-rank memory. If I understand correctly the mainboard in this configuration only has 8 DIMM slots, so using 8x4GB would be quite limiting regarding future upgrades. Edit: if it is any cheaper, you might as well order DDR4-2133 for this CPU.
You know best how much storage you need, maybe you already have some external storage. I would just avoid 1TB HDDs because this really is not much storage and 2-3TB are not that much more expensive.