[pippo2013]

Dear all,

I have to set up two possible configurations for a workstation, one around 7000$ and the otherone around 12000$ , and one of them will be hopefully funded according to the availability of funds.

The machine will be used expecially for Openfoam, and other public domain codes so I don't have problems of licences.
I generally work on unsteady problems and meshes of 2-10 millions cells.

I currently work with an old machine with opteron processors and with an i7 desktop.
I now want to move to intel Xeon, but I don't know which configuration to choose.

Thank you for your help!!

[flotus1]

Is there any particular reason why you want Intel Xeon processors in your next workstation?
If license costs are not an issue, you might as well consider AMD Epyc processors.

[pippo2013]

Thank you Flotus,

I am a newbie and I didn't know Epyc processors, I'have just googled them,
they seem very interesting, although being brand new architecture, there is no much benchmark.
I thought of Xeon since they are trusty, but I will definitely consider the configuration you will propose, both with AMD and/or Intel

I am looking forward to read from you and the other members!
thank you again,

[flotus1]

Since no one else wants to weigh in, here is what I would buy

AMD Epyc:
E-ATX Case (~100$)
Power supply, e.g. Bequiet Dark Power Pro P11 550W (~130$)
Dual-socket board, e.g. Supermicro H11DSi (~550$)
2x AMD Epyc 7301, 16 cores (~2x 920$)
2x Noctua NH-U14S TR4-SP3 (~2x 80$)
16x8GB DDR4-2666 dual-rank (~1600$)
GTX 1060 6GB (~270$)
SSD 250GB, e.g. Samsung 850 Evo (~90$)
+as much storage as you need, maybe even an m.2 SSD with 1-2 TB if you need fast file I/O for your transient simulations

The parts cost ~6000$. Depending on where you buy you can add 1000$-5000$ for assembly, service and warranty. Ask your hardware vendors how much exactly they want to charge you.
I said this a lot, but it should really be a question of weeks until all these parts are available.

On the Intel side some things change
E-ATX Case (~100$)
Power supply, e.g. Bequiet Dark Power Pro P11 550W (~130$)
Dual-socket board, e.g. Supermicro X11DPi-N (~500$)
2x Intel Xeon Gold 6130, 16 cores (~2x 1800$)
2x ask your hardware vendor for a quiet cooling solution, Noctua has not yet released any coolers for this socket
12x16GB DDR4-2666 dual-rank (~2100$)
GTX 1060 6GB (~270$)
SSD 250GB, e.g. Samsung 850 Evo (~90$)
+as much storage as you need, maybe even an m.2 SSD with 1-2 TB if you need fast file I/O for your transient simulations

Prices for the parts here are higher, ~7500$. Same thing, ask your hardware vendors how much they actually charge you for the system.

If you buy from one of the large brands like Dell, Supermicro or HP, you won't be able to pick parts like cases, power supplies or motherboards. Just take what they offer.

[pippo2013]

Thank you so much Flotus!!! You have been really helpful!
I will ask for a quotation on the basis of your suggestion, and in case I get more funds I will bother you again

[flotus1]

One thing I forgot to mention: A quality 550W power supply is sufficient for the configurations I posted.
But if you ever plan on using GPU acceleration at some point in the future, better pick one with 850W or more.

[eric]

That looks like a nice configuration. Would you say that the Threadripper has too low memory bandwith to give good performance for CFD?

[flotus1]

That's not really the point here. With a budget of 7000$+ single-cpu setups are simply not worth considering.

[eric]

That’s true, but if you’re considering a single-socket system, do you think the higher clockspeed of the threadripper would be relevant? I’m running quite a bit of single-core simulations as well, so it’s a trade-off, I guess.

[flotus1]

It is a trade-off indeed. But if a significant portion of your workload is single-threaded, I would rather not choose AMD Threadripper. Intels Sylake-X -despite being a disappointment in many areas- is better for this.

[pippo2013]

Good news for my funds, I have around 12000$ available instead of 7000$ :-)
Hence I have to upgrade my configuration.

Flotus, would you spend all the difference with respect to the amount previously considered for the processors (and RAM)? Which one would you choose (both in case of AMD and Intel Xeon )?

I asked my retailer and they proposed this configuration for about the requested price,
could you please check it and tell me if it is ok or can be optimized at some points?

1 x Mid Tower – 4 x internal bays SAS/SATA–900W Chassis 4U Mid-Tower ATX black. 900W 80+ Gold Certified Single Power Supply.

1 x Dual Xeon C612-Workstation / GPU E-ATX Motherboard. Dual Socket R3 (LGA 2011) for Intel Xeon processor E5- 2600 v4

2 x Xeon 16 -Core E5- 2697Av4 2,6Ghz 40MB Cache FCLGA2011 Socket

8 x DDR4 - 2400 Reg. ECC 16 GB module

1 x Intel C612 SATA III 10 ports Onboard controller.

1 x Intel S4500 960GB 2,5'' SSD SATA II

In this quotation I have to add HD storage, graphic card and cooler, which are missing.

Thank you so much for your invaluable help!!!

[flotus1]

Seems like your retailer is trying to sell you his old stuff he can't get rid of.
Do not buy v4 Xeons anymore. The performance increase for CFD between this generation and Skylake-SP is the largest we had in years.

12000€ is not enough to switch to quad-socket.
So my recommendation for the AMD setup would be to switch to the 24-core processor. The Intel configuration should be near the upper budget limit already.

[pippo2013]

Thank you so much Flotus!!

[pippo2013]

Dear all and dear Flotus,

I'm following your precious dvice according the intel processors, thank you again!
my retailer proposed this solution, could you please check it once more?

CASE SUPERMICRO SC732D3-1200B power supply 1200W
Mainboard Supermicro Dual-socket board, X11DAi-N
2 x Intel Xeon Gold 6130, 16 cores
2 x supermicro fans
12 x 16GB DDR4-2666 dual-rank
GTX 1060 6GB
SSD 250GB, Samsung 850 Evo
2 x HARD DISK WESTERN DIGITAL CAVIAR RED 4TB WD40EFRX SATAIII

thank you so much again

[Simbelmynë]

@pippo2013 and @flotus1

Given the problem size of 2-10 million cells. Do you think 32 cores are much more beneficial compared to 16 (with higher frequency)? Perhaps you plan on running multiple cases simultaneously?

Also, is all that memory really needed?

Seems to me that there should be more cost-efficient solutions, especially if a major part of the simulations are in the 2 million range.

with 12000$ you could also get 10-12 Ryzen 7 computers (96 cores if you like). Or 10-12 Intel 8700K computers (72 cores). Depending on what you do, that may be a better option

[flotus1]

There is always a more cost-effective (aka cheaper) solution.
But I don't think those mainstream processors you mentioned are a good option for CFD in general.

[Simbelmynë]

@flotus1

By cost-effective I do not mean cheaper. Obviously I mean a better price to performance ratio.

Without knowing the specifics of pippo2013's simulations, but assuming that he needs to run at least 10 cases for his analysis. If this would be for the 2 million cell cases, then I think it is a fair assumption that 10 computers with 8700K will be faster than running 10 cases back-to-back on the Intel gold workstation.

If the number of equations to be solved is large and the time-step is very small then it may be prohibitively difficult to solve within a reasonable time on the cheaper computers (i.e. it will take months to complete). However, I doubt that the Intel gold workstation will be able to complete 10 back-to-back simulations in that case either.

With a fast interconnect he could also create a Beowulf cluster. That comparison would be interesting. Normally these type of solutions become less cost-effective if we pay a license cost for each computer, however this was not a problem in the current case.

[pippo2013]

I get your point Simbelmynë, I have a cheap machine I use to run some small case tests.
However, 2 million cells are on the lower side of the range and I definitely need a "proper" CFD workstation

[Simbelmynë]

@pippo2013

If you wish to find a good "mean" then have a look at 7940X, it seems like a very nice CPU (14 cores) with reasonably high frequencies as well as quad channel memory. The only downside is that you need very good cooling for it and that you probably need to delid it if you are going to overclock.

Silicon Lottery sells delidded CPUs with warranty as well as a guarantee to reach a certain overclock.

https://siliconlottery.com/collectio...intel-i9-7940x

A 7940X @ 4.6 GHz will be a beast, but of course a bit risky as well

Anyways, if you go with the workstation I am sure you will be happy. It is also much less work

[flotus1]

Originally Posted by Simbelmynë

@flotus1
By cost-effective I do not mean cheaper. Obviously I mean a better price to performance ratio.

So did I, obviously. The price to performance ratio usually gets worse with higher total performance.
The best price/performance ratio for CFD (considering new hardware) can be found somewhere around the I3-8350k, a $150 quadcore-CPU. But I would not really recommend that unles you really don't have $200 more to spare.