Learning Forum

[harryygee]

Good evening...

Frustrated right now to say the least, I just finished building my computer and installing a P4000 Quadro into my computer so I could do GPU acceleration with ANSYS. I did my research before buying my GPU from this list provided by ansys of already tested GPUs... https://www.ansys.com/-/media/ansys/corporate/files/pdf/solutions/it-professionals/platform-support/graphical-display-graphics-cards-tested-19.pdf?la=en

However, when running a structural model and turning on GPU acceleration I got this error:

so can someone either tell me what I'm doing wrong or did ANSYS publish information that was incorrect?... 

 

[peteroznewman]

Harry,

There are two separate functions that have hardware support: Graphics cards to support the display and GPU Accelerators to support computation. Those two functions require separate cards.

The link you provided is for the graphics cards that support the display and you have purchased a tested display adapter, the P4000 Quadro. This means that your display will function properly. The display adapter uses GPU cores to help it write pixels to the display to provide smooth rotation of the display.

A second hardware card is used to accelerate the computation of the solution using GPU cores and there is a separate list of supported cards for that. Look at the full hardware support list. It clearly lists Graphics Cards separate from GPU Accelerator support.

Here is the list of supported GPU Accelerators.  Notice that different cards have been tested for Mechanical vs. Fluent.

It looks like you are solving Structural models. When I tested GPU accelerators back on ANSYS Mechanical 15, the benefit of a GPU was less than adding one core on the main CPU processor on 8 of my 9 benchmark models. These GPU cards are more expensive than the display adapters. Before you purchase a P100 to accelerate your Mechanical models, I recommend you test how much acceleration it provides for your models. It may be less than you hope for and may not be worth the cost.

Regards, Peter

[harryygee]

Hey Peter,

Thanks for the quick reply, but not the answer I was hoping for... I wish ANSYS would be more clear about these things so I as a college student would be out of a ton of time and money right now. Their lack of clearly and effectively sharing knowledge is really starting to grow old on me. Thanks for clearing this up, however in my error message it says K6000/M6000/P5000/P6000/GP100/GV100 GPUs are recommended? would a p5000 work? or is this ANSYS not effectively communicating again?

Thanks Harry

[tsiriaks]

Hi Harry,

My apologies about the confusion with the docs.

Peter is correct regarding two separate functions and hence we have two separate links listing graphics cards.

For your current card, can you try setting the following environment variable 

ANSGPU_OVERRIDE=1

and see if it makes any difference (might need a reboot to make sure the environment variable takes effect).

Thank you,

Win

[harryygee]

Hey Win Thank you for that info! Where exactly do I input that? The advanced setting in solver settings where it says additional solver commands?
Also is that going to try and use my card to accelerate computations? I'd love to try and get this card to work before I go through the Hassel of selling it and getting a p5000.

Thank you again!

[tsiriaks]

Hi Harry,

It is an environment variable. You can follow the steps here to set it

https://www.java.com/en/download/help/path.xml

Note that the example above is for an environment variable named PATH but in this case you would need to set the name ANSGPU_OVERRIDE  with the value equal to 1. Please reboot after you set this.

Yes, please try this and let us know if it makes any difference.

Thanks,

Win

[harryygee]

Good evening Win,

Good-ish news, what you said to do worked! or at least ANSYS didn't kick me any of the solver errors it did before. However I'm skeptical if its actually utilizing the GPU,

This is my system performance during solving a model and I have turned GPU accel on. However my GPU is not doing much, which would make think Its not accelerating the solving process and the solve time seemed to be about the same. Additionally I got this new warning message which hasn't appear before:

I would try and use the help tab in Mechanical but I can never seem to understand what it wants me to do (sorry, I'm a huge rookie trying to learn some stuff here), so any pointers on how to fix this?

And again thank you so much for the useful info!

[harryygee]

So update: I've figured out how to change the solver (I think), but keep getting that same iterative solve warning, here's what I've:

 Not sure whats going on though...?

[tsiriaks]

Hi Harry,

I'm glad that it doesn't complain about the GPU anymore but for the slow speed, it could be that your current analysis setting can't utilize much of GPU power. Sorry, I'm not really an expert on simulation settings. I will wait for other folks to chime in on your current question.

Thanks,

Win

[harryygee]

No worries Win, thank you for the info you have provided! I am grateful.

[Sandeep Medikonda]

Harry,

You would have to change the solver type under Analysis Settings of your analysis system not under the global settings.

Regards,
Sandeep

[harryygee]

Dear Sandeep and Win, 

I believe we have done it!!!!! The solve time was just cut down to literally nothing and a large spike in my GPU performance occurred during the solve process.

Thank you two for the support! I plan on working on a model for the next few hours so if I run into anymore issues I will let you all know. As for now it seems we've made this work!

grateful for the support!!!

[tsiriaks]

Great news ! I'm glad that it's working for you !

Win

[amp2796]

Hey harrygee,

 

May I know how much simulation time did you save with the GPU accelaration?

Just a rough quantification will help me.

[rajhlinux]

 Well, this is quite interesting. Didn't know you can use the display graphics card to do simulation computations with a little tweaking on Ansys... I was attempted to buy two GPU cards, one for display and another specifically for computation... I would also like to know how much simulation time you saved.