[cairo] Very slow performance

[Billy Biggs]

Soeren Sandmann (sandmann at daimi.au.dk):

> Keith Packard <keithp at keithp.com> writes:
> 
> > > In my tests when I did the MMX stuff in xorg, 128 bit reads/writes
> > > were not an improvement over 64 bit read/writes on the systems I
> > > tested on. On some - but not all - systems, 64 bit was an
> > > improvement over 32 bit.
> > 
> > Were these tests to AGP or PCI video memory?  
> > Or main machine memory?
> 
> They were done on AGP memory I think (on a laptop with an i830
> chipset), so perhaps not that relevant for Cairo.

  Careful with the i8xx chipsets, my experience has been that they
appropriate system memory as video memory and can have very different
performance characteristics from graphics cards with "real" video
memory.

  -Billy