CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Hardware

TR/epyc vs Xeon scalable vs Xeon W vs i9 ansys CFD workstation

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 25, 2020, 20:28
Default TR/epyc vs Xeon scalable vs Xeon W vs i9 ansys CFD workstation
  #1
New Member
 
Join Date: Feb 2020
Posts: 5
Rep Power: 2
edwardn is on a distinguished road
Hello,
I'm trying to determine which is the best CPU for CFD in ansys/Fluent.
The simulation dimensions that this build is intended for are 2D and up to half-million cells.
This system needs to be able to run the simulations very fast and continuously.
The budget for the system is up to 5500$
Please if you can, attach a benchmark that proves your claim.
edwardn is offline   Reply With Quote

Old   April 26, 2020, 06:41
Default
  #2
Senior Member
 
flotus1's Avatar
 
Alex
Join Date: Jun 2012
Location: Germany
Posts: 2,501
Rep Power: 35
flotus1 will become famous soon enoughflotus1 will become famous soon enough
What kind of benchmark would you accept as proof?

In my opinion, you would need to provide more details about the type of simulation you want to run, if you need benchmark-level certainty that any given setup is the best to run your cases. But I doubt that someone would go out of their way to re-create those benchmarks for you. What you could do instead -in addition to adding more info about your simulation setup- is run a strong scaling analysis on your current hardware. And list the hardware specs. From this data, it would be possible to extrapolate the best possible hardware setup with a low margin of error. And tell us how many cores you can use in parallel due to license constraints.
__________________
Please do not send me CFD-related questions via PM
flotus1 is offline   Reply With Quote

Old   April 26, 2020, 07:25
Default
  #3
New Member
 
Join Date: Feb 2020
Posts: 5
Rep Power: 2
edwardn is on a distinguished road
Hello,
thank you for replaying.
I would accept any kind of 2d simulation comparative benchmark with half-million cells or more but not more then few millions cells, Transient solver.
It would be also fine to give me your recommendation without benchmark.
Edit:
I can use up to 16 cores for one simulation but i would like to run several simulations at once.
How can you extrapolate 4 cores 8 threads up to 32 cores and 64 threads? with different CPU tech.
edwardn is offline   Reply With Quote

Old   April 26, 2020, 08:34
Default
  #4
Senior Member
 
flotus1's Avatar
 
Alex
Join Date: Jun 2012
Location: Germany
Posts: 2,501
Rep Power: 35
flotus1 will become famous soon enoughflotus1 will become famous soon enough
Quote:
I can use up to 16 cores for one simulation but i would like to run several simulations at once.
Just to be 100% certain about this one: how many of these 16-thread simulations can you run simultaneously, based on license restrictions? That's quite important here.

Quote:
How can you extrapolate 4 cores 8 threads up to 32 cores and 64 threads? with different CPU tech.
Experience + knowledge about how CFD solvers behave on different types of CPUs.
If the goal here was to extrapolate absolute performance numbers, your doubts would be well justified. But picking the platform that will deliver best performance is somewhat easier. And if you can run several of these simulations at once with lower thread counts, it gets even easier, because strong scaling becomes less of an issue.
__________________
Please do not send me CFD-related questions via PM
flotus1 is offline   Reply With Quote

Old   April 26, 2020, 09:16
Default
  #5
New Member
 
Join Date: Feb 2020
Posts: 5
Rep Power: 2
edwardn is on a distinguished road
I'm using a student Ansys llicense which is limited for 16 cores.
but, isn't limited in the number of simulations. I'm planning to run two simulations at once.
Never mind the benchmark, what is your recommendation for a system based all i have told you until now?
edwardn is offline   Reply With Quote

Old   April 26, 2020, 11:27
Default
  #6
Senior Member
 
flotus1's Avatar
 
Alex
Join Date: Jun 2012
Location: Germany
Posts: 2,501
Rep Power: 35
flotus1 will become famous soon enoughflotus1 will become famous soon enough
Given your budget of 5500$, the best way to spend it is on a system with two AMD Epyc 7302 CPUs. Accompanied by the cheapest way you can fill all 16 DIMM slots with DDR4-3200 reg ECC memory. Most likely 16x8GB. You don't need anything close to this much RAM, but there are no 4GB modules at that frequency. At least none that I am aware of.
And an NVMe SSD for the working directory would probably be a good idea when running several small transient simulations at once.
__________________
Please do not send me CFD-related questions via PM
flotus1 is offline   Reply With Quote

Old   April 26, 2020, 11:57
Default
  #7
New Member
 
Join Date: Feb 2020
Posts: 5
Rep Power: 2
edwardn is on a distinguished road
why i need to fill all ram sluts ?
edwardn is offline   Reply With Quote

Old   April 26, 2020, 12:04
Default
  #8
Senior Member
 
flotus1's Avatar
 
Alex
Join Date: Jun 2012
Location: Germany
Posts: 2,501
Rep Power: 35
flotus1 will become famous soon enoughflotus1 will become famous soon enough
Because of memory channels and bandwidth. Epyc CPUs have 8 memory channels each, so with two of them, you need 16 DIMMs for maximum performance.
__________________
Please do not send me CFD-related questions via PM
flotus1 is offline   Reply With Quote

Old   April 26, 2020, 12:12
Default
  #9
New Member
 
Join Date: Feb 2020
Posts: 5
Rep Power: 2
edwardn is on a distinguished road
thank you very much!
edwardn is offline   Reply With Quote

Old   April 26, 2020, 12:15
Default
  #10
New Member
 
Join Date: Feb 2020
Posts: 3
Rep Power: 2
EagerToLearn is on a distinguished road
I have read an interesting post regarding the memory speed: https://forums.servethehome.com/inde...5/#post-261881

I don't know if this is true, but certainly makes a lot of sense to me. Just throwing it out there.
EagerToLearn is offline   Reply With Quote

Old   April 26, 2020, 12:37
Default
  #11
Senior Member
 
flotus1's Avatar
 
Alex
Join Date: Jun 2012
Location: Germany
Posts: 2,501
Rep Power: 35
flotus1 will become famous soon enoughflotus1 will become famous soon enough
You have to take statements like these with a grain of salt, especially when they are uttered on STH. The people over there are server guys, and they often don't know or don't care how different applications than their own perform. But they are still eager to make generalizations. "Tellerrand" for our German readers
I haven't come across a single real-world benchmark that showed the performance impact of DDR4-3200 vs. DDR4-2933 on Epyc Rome. My money for CFD applications is still on higher bandwidth, and not on lower latency. The benefit of buying DDR4-3200: it doesn't cost that much more compared to 2933, and you can still simply try if your application performs better at DDR4-2933 speeds. The other way round doesn't always work. Memory overclocking on AMD Epyc, even if you remain within the specs of the CPU, is not the most reliable thing in the world.
__________________
Please do not send me CFD-related questions via PM
flotus1 is offline   Reply With Quote

Old   April 29, 2020, 22:18
Default
  #12
Senior Member
 
Erik
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 966
Rep Power: 18
evcelica is on a distinguished road
Isn't the ANSYS student license limited to 512K cells?
evcelica is offline   Reply With Quote

Old   April 30, 2020, 02:54
Default
  #13
Senior Member
 
flotus1's Avatar
 
Alex
Join Date: Jun 2012
Location: Germany
Posts: 2,501
Rep Power: 35
flotus1 will become famous soon enoughflotus1 will become famous soon enough
Yes, it is. OP mentioned half a million cells in his requirements.
__________________
Please do not send me CFD-related questions via PM
flotus1 is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[ICEM] How to create a 3D geometry of spiral tube in ANSYS ICEM CFD 17.1 izu ANSYS Meshing & Geometry 0 March 22, 2017 07:05
Workstation with new E5 Xeon Ivy-bridge Manuelo Hardware 23 November 24, 2014 14:11
Ansys 14.5 CFD to structural analysis VJ0085 ANSYS 0 October 16, 2013 12:16
Using ICEM CFD to repair/edit ANSYS Meshing Kaaji1359 ANSYS 2 July 30, 2013 10:28
Which is better to develop in-house CFD code or to buy a available CFD package. Tareq Al-shaalan Main CFD Forum 10 June 12, 1999 23:27


All times are GMT -4. The time now is 19:56.