[x264-devel] Re: Speed-up method

[Guillaume POIRIER]

Hi,

On 3/3/07, telomere 1 <telomere1 at gmail.com> wrote:
> What do you think?
>
>
> QX6700
> 27.9GFlops
>
> Geforce 8800GTX
> (MADD(2flops) + MUL(1flop)) × 1,350 MHz × 128 SPs ＝ 518.4G Flops

x264 spends the vast majority of its time doing integer computations,
not floats.

Last time I looked at it, integer performance on GPU isn't that great
compared to its float performance.
I'd like to point out that communications between CPU and GPU are
expensive, and that there's no shared memory between them.

All in all, I think it's pretty damn hard to get great speed-ups on
integer code with current generations of GPUs.

Guillaume