Weird - 8500LE works in windows but borked in Linux
 

I have a curiosity - a 128MB Hercules 8500LE. This replaced another 8500LE
in my spare PC which I moved to another system because of its faster memory
(3.6ns) which would allow more oversclocking. Despite being a 128MB card,
windows only recognises 64MB. This does NOT appear to be a software problem
as, despite exhaustive tweaking and twiddling, NOTHING (including reflashing
the card's bios with the genuine Hercules bios) can get Windows to see more
than 64MB. However, the card works perfectly in windows - quake3, unreal
tournamant 2003 etc all run fine.

Now the interesting part. Under Linux (Mandrake 9.2) the card is unusable
for any 3d applications - horrible artifacts, flashing blocks of pixels and
a fine checkerboard overlay in all 3d apps including quake3, unreal
tournamant 2003 and glxgears. I do not believe that this is a software
problem as the previous 8500LE worked flawlessly under the same
installlation of Linux and nothing in the system has been changed apart from
the graphics card. The mystery is how the card manages to render perfectly
under windows and is completely borked under linux. I am pretty sure that
the linux problem must be related to the missing 64MB. Anyone got any ideas
to explain the difference between windows and linux for this card?

--
Tony

I have a curiosity - a 128MB Hercules 8500LE. This replaced another 8500LE
in my spare PC which I moved to another system because of its faster memory
(3.6ns) which would allow more oversclocking. Despite being a 128MB card,
windows only recognises 64MB. This does NOT appear to be a software problem
as, despite exhaustive tweaking and twiddling, NOTHING (including reflashing
the card's bios with the genuine Hercules bios) can get Windows to see more
than 64MB. However, the card works perfectly in windows - quake3, unreal
tournamant 2003 etc all run fine.

Now the interesting part. Under Linux (Mandrake 9.2) the card is unusable
for any 3d applications - horrible artifacts, flashing blocks of pixels and
a fine checkerboard overlay in all 3d apps including quake3, unreal
tournamant 2003 and glxgears. I do not believe that this is a software
problem as the previous 8500LE worked flawlessly under the same
installlation of Linux and nothing in the system has been changed apart from
the graphics card. The mystery is how the card manages to render perfectly
under windows and is completely borked under linux. I am pretty sure that
the linux problem must be related to the missing 64MB. Anyone got any ideas
to explain the difference between windows and linux for this card?

My guess is that the card has one or more bad RAM chips. The Windows
driver recognizes this and disables the half of the memory bus it's on,
yielding 64MB on a 64-bit bus. The Linux driver doesn't detect the bad
memory and attempts to use all of it, resulting in serious b0rkage.

This is only a wild guess, but it would seem to be a possibility, since
often the only visible difference between a 128-bit card and a 64-bit
card is that half the memory chips are missing...