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about video card acceleration

Posted: Tue Mar 29, 2011 1:35 am
by zjuer
Hello everyone,
I want to buy a video card to accelerate abinit, my problem is (1) Is the capacity of the memory of video card important, is there a great difference between a video card with 1GB memory and that with 2GB memory? Is gtx460 proper for my purpose, or what's your recommendation, around $200? Thanks.

Re: about video card acceleration

Posted: Tue Mar 29, 2011 10:51 pm
by pouillon
This is not as simple as that, and you may not always get better performances with more memory, since a lot of data has to be transferred from the main memory to the GPU - and vice-versa. These transfers can become a bottleneck under some circumstances, and actually slow down the calculations.

There are in any case many criteria to take into account:
  • the kind of calculations you want to perform;
  • the typical size of your systems;
  • the tunability of your input parameters for this kind of architecture;
  • whether the GPU is connected to a screen, in which case performances might drop significantly;
  • the capabilities and limitations of the implementation;
  • ...
Buying a GPU only for Abinit might also be a little overkill. You probably should think about using it for other codes as well.

Re: about video card acceleration

Posted: Wed Mar 30, 2011 4:20 am
by zjuer
Thank you for your enlightening suggestions.