[Openchrome-users] KM800? Is this the same as K8M800

[Luc Verhaegen]

On Mon, Oct 01, 2007 at 09:51:08PM +0200, Benno Schulenberg wrote:
> canuk guy wrote:
> > So let me get this straight I can change the 64mb to 128mb. That 
> > would be awesome. Because I had used it and like I said I can
> > almost get it to play HD, it stutters just a little.
> 
> This is a bandwidth issue.  Increasing the amount of shared memory 
> won't help with that.

You can easily avoid HyperTransport bandwidth issues if you avoid 
round-trips.

Disable DMA, disable the HQV, and you disable 4 of 5 round-trips. The 
copy from RAM to an unmapped part of RAM is rather cheap. A single read 
from FB out onto the screen, plus reading the colour key should be 
pretty doable.

Some fifo hacking and probably setting the full screen bit (and no 
colorkey) will then remove the last bits of trouble completely, when 
still needed, that is.

Luc Verhaegen.
SUSE/Novell X Driver Developer.
http://unichrome.sf.net/