Workstation for ~€7-800 - 5820k based setup still best bet?
 

Hello,

I am considering putting together a budget workstation build as my time using my supervisors 2xE5-2637 V4 setup will soon expire.

So, my cases are most commonly <5M cells, transient, single/multiphase flows in OpenFOAM. No reactions etc.

At a budget of around ~€7-800 is the setup proposed below by flotus1 still my best bet?

If so, since the original post is now a year old, could I perhaps upgrade on some parameters due to price drop over time?

It seems that a dual E5-2xxx V2/V3 setup is out of reach at this budget and perhaps it is not even optimal for my type of cases.

If I have overlooked better alternatives, please fell free to inform me.

Thanks in advance!

- Rasmus

Hi Rasmus,

For your reference, I bought the following used PC in Denmark 3 years ago for 1350 EUR (10000DKK):
i7-5820K
Asus RAMPAGE V EXTREME X99 - 2011-v3
32GB Corsair VENGEANCE LPX red
Samsung 950 PRO NVMe M.2 512GB
GTX 1080 Founders Edition
Corsair AX760i
Corsair Graphite 760T
Custom water cooling (EKWB) on the CPU & GPU
Windows 10 home

I would guess that for 700EUR-800EUR, you would get a similar PC. If you find something with a worse graphics card, then you can get a 6800k instead, for example, https://www.dba.dk/selvbyg-overclock...id-1063022322/.

If you have an easy to run OpenFOAM setup, then can perform a test for you if needed.

It depends...
If your workflow mostly consists of pre- and post-processing, and solver times are less critical, X99 is still a valid option. Especially since DDR4 memory is still cheap.
If you want to reduce the solver times for these transient simulations as much as possible, then dual-socket 2011 is the better choice.

It is entirely possible to get a get a dual-socket 2011 system up and running for 800€. You can either search for decommissioned workstations from that era, or search for a good deal on a used motherboard.
There is even another option: the cheap "dual X79" motherboards you can find on sites like aliexpress. Make sure to get one with 4 DIMM slots per CPU, and be prepared for long shipping times.
Even dual-socket 2011-v3 might be possible with 800$ thanks to cheap motherboards from that site, depending on how much time you want to spend searching for good prices for CPUs and memory.

@Jeggi: Thank you so much for your reply and thank you for offering to run a sample case. Also nice to find a fellow Dane here! I will remember your offer on running a test case ;)

@flotus1: I was hoping to get a reply from you on this topic. I am definitely more biased towards reducing transient solver time as it will not be performing heavy pre-/postprocessing tasks. These E5's typically have lower clock frequencies than top range i7s. Is that not a significant disadvantage?

And regarding GPUs, how cheap a unit can I get away with? Would something cheaper than a 2 GB GTX 750 Ti cripple my overall setup too much?

It is, hence the question what is more important to you. Single- or lightly threaded workloads like pre- and post-processing benefit from higher clock speeds.
The solver phase on the other hand benefits from more cores, as long as memory bandwidth can keep up. Any single CPU for the X99 platform will be slower than dual-socket 2011(-v3), because scaling stops at around 6 cores, due to memory bandwidth limit. No matter how high you crank up frequencies.

Paraview does a pretty good job at remaining usable with low-end GPUs. Having enough VRAM to fit the whole model is more important to the user experience than raw performance. So I would advise against less than 2GB of VRAM. The GTX 750TI is probably not the cheapest option, because it still has the reputation of being a budget gaming option.

Thank you for your feedback, flotus1. I feel well informed to go part hunting on eBay now :)