G400 MAX, Win2K and AGP aperture size

[D0ug]

I have a G400 MAX with Win2K SP2 using the 5.82 drivers. It seems that the G400 is unable to use more then about 15MB of system memory as video memory via the AGP aperture setting. I currently have the AGP aperture setting set to 64MB, but 3dmark says that there is only about 47MB of total video memory available. Why is there not 96MB available? Memory usage is not an issue. I have 1GB of ram in this system, and about 830MB of that RAM is free.

[Guru]

AGP aperture should be set to 256mb also check that you have the "memory hole" disabled in the BIOS, you should be able to find it under the advanced chipset features menu!

[Heed]

Read down a few posts here (the first post by ralf, I believe):

http://forums.murc.ws/showthread.php?s=&threadid=33214&pagenumber=3

[D0ug]

Thanks for the replies. Guru, I changed my AGP aperture to 256 and memory hole was already disabled. This did not fix the problem. Heed, thanks for the link. Does anyone know if this is a driver issue? I assume under Win9x that the G400 dosn't have this problem, and other non Matrox cards dont seem to have this problem with Win2k, so this would make it seem like a driver issue to me. If so does anyone know if Matrox plans to fix it?

[Heed]

I'm pretty sure it's a win2k issue. Are you sure other cards don't have this problem under 2k?

[D0ug]

I have a friend with a 32MB Geforce 256 and Win2k. The 64MB texture test in 3dmark runs fine on that card.

[Heed]

Hmmm, I don't know then. You'll have to wait for someone more knowledgable than myself-- maybe one of the betaboys could give you more info. I run win2k too, so I'd be interested in the answer (I gave up doing benches long ago).

Could be because the g400 uses DIME transfers, but that's just a guess.

[D0ug]

I also did a quick search on Google, and this is all I found that described the same problem. http://dzeus.student.utwente.nl/g400/win2kfaq.html That just happens to be another site about the G400. I think there would be lots of complaints on the web if this was a Win2K issue.

[Heed]

dzeus is a long time member of this board.

"- AGP Aperture Size - 256 to about anything higher than say 48MB, since settings that low tend to lessen the amount of AGP texture memory, or disable AGP texturing completely. It probably won't make much of a difference, as Win2k can't use more than 16MB of AGP textures"

That's from his FAQ

[D0ug]

Did some more looking around and found this http://www.reactorcritical.com/perfo...-win2k_3.shtml States that Win2k supports DiME, but the drivers must have support for it. I guess at the time this was written the G400 was the only card that supported DiME in Win2K and this was under DirectX only.