Le Ven 27 mars 2009 03:00, Fernando Cacciola a écrit :
To measure the convenience of using the GPU against the slow down of the bus bottleneck depends on what you offload to the GPU.
The OP want to offoad 4 element vector operation ont he GPU, one at a time ... It doesn't requir emuch more analysis to see it'll fail.
Stating that *G*raphics algorithms, among all things, wouldn't gain much from using the *Graphics*PU can't make sense IMO. Otherwise, there wouldn't be any reason to have a GPU to begin with (or GPUs would still be just dumb renderers as they used to be in the distant past) FWIW you can google for the term GPGPU to see how the field of computing in the GPU is advancing.
We've been digging GPGPU since two years now so we start to knwo when it fails and when it does not. Small amount of data is usually a bad start, small amount of dtata + few operations is road to disaster. Hence my remark concerning the OP idea. FYI, some graphic algorithm horribly fail in term of efficiency on GPU. I don't consider havign a speed-up of 6 or 8 with a GPU for n optical flow algortihm a success. BEst GPGPU alorithm efficiency are achieved with algorithm that mimick the operation density of 3D rendering (database search, N-bod like applciation etc). Offloading a few 1x4 vector multiply won't cut it