[JohnAB]

Hello,

I have been using Starccm for 2 phase flows and all sorts of sims with 10M-100M cells, but that was 3-4 years ago.
Today, what would you guys use as hardware if you had to build your own workstation for $10k?

Better off with one i9 intel and 128gb DDR4 ram, add a nvidia rtx a6000 in the mix just in case my simulation can run on GPU?

[flotus1]

Before buying a GPU for your applications, you need to be absolutely sure that what you want to do is supported with GPU acceleration. Otherwise you end up with a 5000€ space heater. That involves EVERY aspect of the simulations you run.
And equally important: pick the right GPU. An RTX A6000 for example has very low FP64 performance. Which means no double precision solver with this 5000€ card. And you need to check that memory on the GPUs is enough for your largest models.

Unless you can verify beforehand that your simulations benefit greatly from GPU acceleration, stick with CPUs.
Which one depends mostly on your CCM+ licenses. I.e. how many threads you are allowed to use for a parallel simulation.
Chances are, any "I9" CPU is not the best option by a large margin.

[JohnAB]

Thanks!
I am going to stick with what I know, i.e. CPU, and as you say, it is quite likely that what I do (free surface flow, 2 phases, sometimes overset mesh) is not supported with GPU acceleration.

I may only have serial session / 1 core to begin with, and depending on results and cost, probably expand from there.
I was always using unlimited power before, so I'm very new to the 1 core limitation.
I have the feeling I won't stay at 1 core for long so might buy the CPU with that in mind?

I have read dual cpu is the way to go for the types of sims I do (50ish M cells, used to take 24h to run on unlimited power). But the question is, does it even makes sense?
I also read all dimms need to be populated, and since my simulations take at least 50-60GB of memory,

I was thinking of going:

2x Intel Xeon W3335 (8 channels per cpu),
RAM: 16x8GB DDR4 reg ECC (still need to find it),
basic GPU,

If you have a recommendation for who can build it in the US that could help, I'm really not used to deal hardware...

thanks for your time!

[flotus1]

All right, if all you have is a single serial license (or up to ~4 threads), the latest-gen desktop CPUs are indeed your best bet. An I9-13900k will be the fastest choice. Though the I5-13600k won't be much slower, at much lower cost.

But running simulations with 50 million cells, potentially as transient multiphase, just isn't feasible with a single thread.
10000€ should allow you to get much better suited hardware once you get more/unlimited parallel licenses. Dual-socket is indeed the way to go here.
Xeon-W CPUs are single-socket only though.
If we are talking about 10000€ worth of parts, 2x AMD Epyc 7573X is the best you can get.
From some system integrator, the budget should be enough for 2x AMD Epyc 7443.
Or on the Intel side of things: 2x Intel Xeon Gold 6338, 6342, or 6348 are good candidates.
I would not be too stingy with memory, DDR4 is pretty cheap these days. 256GB total as 16x16GB DDR4-3200 reg ECC can be had for less than 1000€ retail these days.

It all hinges on the licenses. Since they are probably more expensive than the workstation, especially over a few years, knowing how many threads you can use comes first. Then you can pick the best hardware for this thread count. Things change with e.g. 16 threads vs unlimited thread count.
No idea who could build you a functioning workstation with these specs in the US, sorry. I've had a hard enough time finding someone in Europe recently, and they severely under-delivered.

[JohnAB]

Thanks again!
The EYPC processors you mentionned seem a bit too pricy as it comes up to $12,000 - $15,000 workstations when I try to build it.

It seems I should not go for EPYC Milan and stay on EPYC Rome in order to meet budget.
From there, looking at benchmarks sites like cpubenchmark.net , the 7302 seems very interesting and one of the best quality/price.


I went to https://www.titancomputers.com/Titan...ies-p/s375.htm

And I believe I would go with:

2x AMD EPYC Rome 7302 3.0Ghz 128MB cache 32 cores 64 threads;
Supermicro H11DSI-B – dual AMD EPYC processors motherboard;
256GB (16x16GB) 288-pin DDR4 SDRAM 3200 ECC;
Power: standard is 1000W – 80 plus gold certified, but should I pick 1200W or even 2000W ? I do not understand what this is going to change, I’m lost here.
OS: Windows 10 Pro 64-bit, or should I go “windows 10 pro for workstation” ?
Communications: network and wireless, I believe I do not need to worry about that if that’s my only 1 workstation?

This is about $6500 so far, it seems to me that’s a good deal for what I get. It seems that this setup is ready for more starccm licenses, without being excessively expensive if I begin with only 1 serial license (?).

I am also having trouble getting a starccm quote or price estimates for the different types of license, I didn't expect it to be so difficult to find

[flotus1]

I'm not a huge fan of stepping down to Epyc Rome in this situation.
They are great value on the used market. But if you are buying new from some SI, the savings -if any- are not worth the downgrade. Let's not forget that Rome is the second generation of AMDs Epyc processors, and the fourth generation "Genoa" has already been released. You are helping your SI get rid of old stock.

There are other options for Milan:
7313 - 16 cores, ~1150€ retail price. This is the equivalent to the 7302 in your configuration
7413 - 24 cores, ~1950€ retail price. A slightly lower clocked version of the 7443 I mentioned earlier

Also beware of the form factor. You linked a rackmount server. That's fine if this is what you had in mind, but it won't be of use if you actually wanted a workstation that sits under your desk.

OS: Windows 10 Pro 64-bit, or should I go “windows 10 pro for workstation” ?

Windows 10 Pro is fine for this. Workstation is needed for extreme core counts and stuff like four CPUs.

Power: standard is 1000W – 80 plus gold certified, but should I pick 1200W or even 2000W ? I do not understand what this is going to change, I’m lost here.

A 1000W PSU is PLENTY for this PC. With prices for electricity soaring, I would invest in at least 80Plus Platinum efficiency.

Communications: network and wireless, I believe I do not need to worry about that if that’s my only 1 workstation?

Nothing fancy needed here. The motherboard will have at least Gigabit Ethernet. Just specify wireless LAN if you need it, because that's not included on server boards.

I am also having trouble getting a starccm quote or price estimates for the different types of license, I didn't expect it to be so difficult to find

That's normal. They don't want fixed prices to be out there, you have to discuss prices with them directly. But really, do that before buying the workstation