[Slash]

Hello, I'm a mechanical engineer. I'm thinking about buying a new workstation/server to do FEM structural simulations (abaqus, ansys, nastran etc). My question is: is it better to buy a two socket Intel Xeon scalable Silver 4216 or 4214 or a single AMD Ryzen threadripper 3960X?

The thing is that the xeon processors are well known in server industry and the AMD proposal in that field is the Epyc one and not Ryzen. But at a price of 1600 euros the Ryzen 3960X has the triple of scores in passmark benchmark, is that also true for our FEM simulations?

[flotus1]

No, it isn't.
If you need a machine mostly for FEM, the Epyc lineup is the better choice, both compared to Xeon and Threadripper. For example Epyc 7402P.
There are even some very cheap offers for them: https://www.provantage.com/hpe-p16664-b21~7CMPTCRA.htm

[Slash]

The Epyc could be a great choice. Can you explain the reason for that?

[flotus1]

Compared to Threadripper, it has twice the amount of memory channels: 8 vs 4.
With codes based on FVM and FEM, TR CPUs quickly run into a memory bandwidth limit. They start out slightly faster on a single core, but scaling quickly drops off at around 8-12 cores. There are plenty of examples in this sub-forum.
Epyc CPUs on the other hand are a little bit slower per core due to the lower clock speed, but scale up to twice the amount of cores, thus end up being much faster when using more than 8 cores.

[Slash]

Thanks flotus1. Some time ago I saw a benchmark dedicated to server system (SPEC cpu 2017) that I've attached here. The test showed that epyc 7402P processors have a mean base score of about 93 in floating point speed respect to xeon 4214 processor that has about 93 for the two socket configuration and 57 for the single socket. Considering the price for Italy that is the country where I live, the single Epyc cost about 1550 euros respect to the dual xeon 4214 that cost about 1600 euros. With the epycs there would be the possibility to add another cpu in future, right?

[flotus1]

Not if you buy an Epyc with a "P" suffix. These only work in a single-CPU configuration.
But there are similarly priced CPUs which are 2P capable, for example the 7352.

[Slash]

Thanks, the 7352 has a similar score of about 90. Can you send me the links of the examples in this subforum?

[flotus1]

<OpenFOAM benchmarks on various hardware

[Slash]

Thanks flotus1. It is very interesting. Do you know a workstation motherboard for Epyc sp3 socket, like asus or gigabyte? I see some supermicro solutions but they are mostly designed for servers rather than for workstations.

[flotus1]

Unfortunately, all SP3 motherboards are geared towards server usage.
If there was anything more workstation-y, I would have bought that myself.

For dual-socket, pretty much the only option right now for a system builder is Supermicro H11DSI(-NT). I am using it myself.
For compatibility with Rome CPUs, contact your seller in advance and make sure you get revision 2.x of that board. Older revisions are not compatible with the second generation of Epyc CPUs.
You will miss out on PCIe 4.0 with H11 motherboards. H12 has been announced a while back, but I am no longer sure it will ever see the light of day.

[Slash]

And for single socket?

[flotus1]

Same problem.
I would probably pick between ASRock Rack RomeD8-2T and Gigabyte MZ32-AR0

[Slash]

Hi flotus, did you know the difference between the supermicro h11dsi and h11dsi-nt?

[flotus1]

The NT version has built-in 10Gigabit Ethernet. Otherwise it's the same board.

[Slash]

Ok thanks. The revision 2 has also the support for 3200 MHz dram memory right? Are you using this type of DRAM? I'm interested in supermicro motherboard because i would buy one processor now and another in the future to upgrade the system.

[flotus1]

Yes, rev. 2.x supports DDR4-3200.
https://www.supermicro.com/en/produc...oard/H11DSi-NT

[Slash]

I see that it supports only hynix module for 16gb 3200mhz. I'm having some trouble to find it, did you have these modules? where did you find them? (not China or USA because of shipping time)

[flotus1]

You are probably looking at the tested memory list. Hence not an exhaustive list of all memory modules that will work with this board. There is a fair amount of standardization involved in memory modules, so others will will usually work just fine.
I started with modules that were not on the tested list, then later upgraded to modules that happened to be on the list. I bought them mostly because they were the cheapest available.

As long as you stick to well-known brands, memory modules not on the QVL will work most of the time.
https://geizhals.eu/?cat=ramddr3&xf=..._RDIMM+mit+ECC

[Slash]

Did you suggest only ECC memory for FEM analysis right?

[flotus1]

There is no point in discussing this (much broader) topic in this particular context.
Epyc CPUs only work with RDIMM and LRDIMM, and there is basically no RDIMM without ECC. So just buy ECC RDIMM.