[Chr1st0ph3r93]

Hello CFD-Online!

I am a graduate mechanical engineer currently trying to find the best CFD-PC spec for approximately £6k for use of OpenFOAM at my place of work. Currently I have found a specification that suits the budget and (to my best knowledge) is a suitable workstation capable of running up to 50M (rarely) cell steady-state/transient turbulent simulations. More complicated cases may be run in the future, so this PC must have relatively good headroom for these potentially expensive simulations.

The PC spec I found is below;
- 2x Intel Xeon Gold 5220 18-core (2.2GHz, 3.9GHz turbo, 24.75MB L3 cache)
- 8x 32GB Kingston DDR4 2666MHz ECC registered RAM
- 2x PNY Quadro RTX 4000 8GB GDDR6, 2304 CUDA cores
- 480GB 2.5" SSD, 520MB/r, 450MB/w
- 4TB 3.5" HDD, 5400RPM

My main questions are;
- are these specs reasonable?
- is it better to have 2 lower spec CPU's or 1 higher spec?
- same as previous question but for GPU?

Any help and/or advice would be greatly appreciated.

Thanks in advance.

Chris

[flotus1]

- are these specs reasonable?

Partially. For these CPUs you need 12 DIMMs, not 8. They each have 6 memory channels.
It has been shown that AMD Epyc CPUs deliver more performance/$ in OpenFOAM. See the pinned thread here.

is it better to have 2 lower spec CPU's or 1 higher spec?

Absolutely, two cheaper CPUs are better than one expensive CPU.

- same as previous question but for GPU?

I would rather question the purpose of an expensive GPU for this workstation.
If you want to use them for GPU acceleration in OpenFOAM, I guess you are already familiar with this feature and know that it can benefit your workflow?
The Quadro RTX 4000 has no double precision performance to speak of. For computing in single precision you might as well buy cheaper consumer cards. Anyway, you will be limited by the amount of memory these cards have. There is no way to run a 50M cell case on GPUs in this price range.
In case you just need a graphics card, something much cheaper like a GTX 1060/1660 6GB would suffice.