Performance change from X in Fedora Core 4 to Fedora Core 5
felix at bellaby.plus.com
Thu Jul 13 05:47:26 PDT 2006
On Thu, 2006-07-13 at 13:44 +0200, Clemens Eisserer wrote:
> > Since nVidia are managing to pipeline to these pixmaps, it is likely
> > that the alloc/dealloc process is an illusion. Presumably, they are
> > firing the drawing operations somewhere into a permanently allocated
> > area of video memory and just making it look like new memory to the
> > client side. The GPU has to know where the final rastering is to go
> > somewhere before the end of the pipeline and probably needs the info
> > right at the start.
> Sorry I think you misunderstood me ;-)
> Nobody pipelines anything, nvidia developers just confirmed that
> allocation/deallication is a really bad thing and that this is the
> reason why so much time is spent inside of malloc and software
> rendering routines.
> They first allocate a pixmap in RAM and only if its "worth" to put it
> into VRAM (first copyarea?) the upload it into vram. However future
> nvidia drivers will allow to disable that feature with the result that
> a lot of time is spent waiting for the GPU.
> Allocation of mb-sized resources can never we a no-brainer...
I thought it sounded too good to be true.
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