What sort of AGP problems are you seeing? We are seeing poor performance with > 4GB.
Yes, it's pathetic with 8GB installed. Bandwidth across the AGP connector is about 17MB/s, due mostly to a bogus uncachable MTRR entry that BIOS sets up, the removal of which blows the system away (reason unknown; I don't know why it's there in the first place). With 1GB installed, the frame buffer can be mapped write-combining and AGP b/w jumps to about 250MB/s. This is the fastest I've been able to observe actual data transport (about 1x AGP) depite the fact that the AGP connector is signalling as fast as 8x AGP v3 (on an ATI X1). The 8151 is on its own HT link, and that link is running at 16 bit, 600 MHz, so there's no architectural reason it should be this slow. There is clearly something incredibly and obviously wrong going on with way things are getting set up on the board, and being as it's been weeks since I initially started talking to Tyan and have heard nothing back, I'm not hopeful that they're even bothered to reproduce the problem let alone do anything about it. I am afraid they're of the mindset that "picture on screen == works" -- I sure wish they'd correct this misconception if it is one. Anyway, I'm still of the belief that there's just a crazy memory mapping and requests to AGP are getting stalled/deferred because of some deranged table entries somewhere. I haven't found them yet 'tho. :) See my posts to the suse-amd64 archives for Oct/Nov timeframe for more details and pointers to a benchmark you can play with if you're that motivated. I really want to start making my own boards...
Well, I'll keep my fingers crossed. :-)
Yeah. -mcq