How is GPU TDP% stability/stress test performed?

[Adam_W]

Hi,

 

When I run the GPU stress test I get pulse forms that looks like this:

 

http://i.imgur.com/LOD92Sb.png

 

When running Furmark Burn test with 2x MSAA full screen 1080i I get this:

 

http://i.imgur.com/VXrn7U3.png  (Ignore first bump in the graph please)

 

Why is the Aida64 fluctuating? Or what does it do or how does it really test the GPU?

 

Thanks.

[Fiery]

Please note that unlike 3DMark, Furmark or many other 3D benchmarks or 3D games, AIDA64 uses GPGPU compute tasks (via OpenCL) to put stress on the GPUs and APUs.  It means, it has to call OpenCL to first copy a block of memory from system memory into the video memory, then start a program that performs the actual computation, and then when it's finished, it has to copy the memory back from the video memory to the system memory, in order to let it verify the results.  And since all those tasks have to go through OpenCL driver, then the video driver (ForceWare in your case), the PCI Express link, and also the GPU itself, there's a lot of latency and bottlenecks involved in the process.  It effectively means the GPU may not be driven 100% constantly, but sometimes a downward spike may appear when the OpenCL driver, the PCI Express link or the video driver lags a bit.  That's normal, and can only be avoided by directly programming the GPU (which is impossible), or using a 3D scene instead of a GPGPU code.

 

However, the advantage of GPGPU stress test over 3D scenes is that using GPGPU code it's much easier to stress all available GPUs simultaneously.

 

 

Regards,

Fiery

[Adam_W]

Thank you for taking the time to reply Fiery