[MioMio]

Hey Everybody,


i'm configurating a new workstation for CFX calculations (ANSYS) and CAD (Solid Works). I will use Win 10 or 11 on the system.


The mesh used in the cfd calculations will have a estimated maximum node count of 10 - 12 *10^6 The setups are mostly radial compressors with medium air or steam in RANS mode. The Intend of the calculations are to proove our compressor desing and calculate compressor maps/speed lines. In the future i want to run parametric comprssor models for optimization of the geometry.



From now until about 3 years i can run the cfd on 516 Cores (4 HPC Packs) and after that we will have a least 1 HPC Pack = 12 Cores. Maybe we will switch then to other, non core restricted software, but who knows...


At first i have read the guide in the forum "General recommendations for CFD hardware".
ATM i'v no clue how flexible the budget is.
So here are 3 options and my question is in general:


- Are the components well choosen to work together?
- Could there be problems running a CFD while working on CAD projects? (i think this will be a trade of cores per program and finding a good balance for both)

- Is it worth to have a dual system with 32 cores instead of a single cpu system with 16 or 24 cores?
- some Brand/Product recommendations forDDR4 ECC registered 3200 MHz RAM (The manufacturer of the workstation will choose the RAM depending on what is available on the market, so i will not know exactly what i'll get, but maybe i can choose from some products.)


Single CPU system:
- Supermicro Server Mainboard H12SSL-I
- AMD EPYC Milan 7313 Prozessor 3.0 GHz (16 Cores) or
AMD EPYC Milan 74F3 Prozessor 3.2 GHz (24 Cores)
- Memory 128 GB (8x 16 GB) DDR4 ECC registered 3200 MHz

- PNY NVIDIA RTX A2000

- 1.0 TB Samsung PM9A1 M.2 NVMe SSD


Dual CPU system:
- Supermicro Server Mainboard H12DSi-N6
- 2x AMD EPYC Milan 7313 Prozessor 3.0 GHz (16 Cores)
- Memory 128 GB (16x 8 GB) DDR4 ECC registered 3200 MHz

- PNY NVIDIA RTX A2000
- 2.0 TB Samsung PM9A1 M.2 NVMe SSD



Thanks in advance for answering my questions

[wkernkamp]

Originally Posted by MioMio

Hey Everybody,

From now until about 3 years i can run the cfd on 516 Cores (4 HPC Packs) and after that we will have a least 1 HPC Pack = 12 Cores. Maybe we will switch then to other, non core restricted software, but who knows...

Can you verify that your current 4 HPC Packs allow 516 Cores. This means unrestricted for your proposed machines. However, when I look at the future single HPC pack with just 12 cores, I wonder if there is a typo in the current limit.

[wkernkamp]

Originally Posted by MioMio

Hey Everybody,

The mesh used in the cfd calculations will have a estimated maximum node count of 10 - 12 *10^6 The setups are mostly radial compressors with medium air or steam in RANS mode. The Intend of the calculations are to proove our compressor desing and calculate compressor maps/speed lines. In the future i want to run parametric comprssor models for optimization of the geometry

Your cfd problem size is not overly big, so a single processor could do a decent job. However, when you attempt optimization, the solution times will grow by perhaps an order of magnitude or more. One option you have is to select the dual socket motherboard but populate just one socket and half the memory slots while selecting a high performance part (the 24 core if the choice is between the two processors you listed). In a year or two, when you are ready to do optimization studies, you can get the second processor which will be a lot cheaper by then.

[wkernkamp]

Originally Posted by MioMio

Hey Everybody,

From now until about 3 years i can run the cfd on 516 Cores (4 HPC Packs) and after that we will have a least 1 HPC Pack = 12 Cores. Maybe we will switch then to other, non core restricted software, but who knows...

- AMD EPYC Milan 7313 Prozessor 3.0 GHz (16 Cores) or
- AMD EPYC Milan 74F3 Prozessor 3.2 GHz (24 Cores)

- 1.0 TB Samsung PM9A1 M.2 NVMe SSD
- 2.0 TB Samsung PM9A1 M.2 NVMe SSD

I agree that 3 years is a long time. In a professional heavy use environment it may make more sense to replace the system in three years.


If there is a concern for a looming reduction in core licenses, it is obviously better to go to higher frequency parts. This indicates that the 74F3 is preferred among the two parts you list.


I saw that your single socket board has a proposed 1TB Nvme, while the dual socket has a 2TB Nvme. This is probably just a mistake, but would make a price comparison more unfavorable for the dual socket system (if given to the system builder as a spec).

[MioMio]

Originally Posted by wkernkamp

Can you verify that your current 4 HPC Packs allow 516 Cores. This means unrestricted for your proposed machines. However, when I look at the future single HPC pack with just 12 cores, I wonder if there is a typo in the current limit.

Yes we have 4 HPC Packs available (i see them in the licence server list of used/available licences). Due to the information i'v taken form this website, 516 cores in total can be used when one user takes all the cores. My company has purchased an Ansys licence pack for start up companys. It was significant cheaper to buy this product, than buying just CFX + 1 HPC pack. We can order this licence package two more times/years.

Originally Posted by wkernkamp

Your cfd problem size is not overly big, so a single processor could do a decent job. However, when you attempt optimization, the solution times will grow by perhaps an order of magnitude or more. One option you have is to select the dual socket motherboard but populate just one socket and half the memory slots while selecting a high performance part (the 24 core if the choice is between the two processors you listed). In a year or two, when you are ready to do optimization studies, you can get the second processor which will be a lot cheaper by then.

Originally Posted by wkernkamp

I agree that 3 years is a long time. In a professional heavy use environment it may make more sense to replace the system in three years.

Originally Posted by wkernkamp

If there is a concern for a looming reduction in core licenses, it is obviously better to go to higher frequency parts. This indicates that the 74F3 is preferred among the two parts you list.

Okay, so i tink i'll suggest my superviser to buy the 2 core system if we want to spent more money and the 24 core single system it we want to buy the cheaper version. Thank you for sharing your thoughts wkernkamp.