Joost, Quite a while ago I did the same on my Tyan S2875 and linux indeed started seeing all 4GB of memory. BUT! As soon as application were trying to access high memory regions, the system crashed. I would suggest first to test the memory usage. The simplest test is copying a dvd image or a file of comparable size so it would get cached into memory. Max Joost Kraaijeveld wrote:
I have found my memory.One must set two seperate setting in the BIOS that both are not ducumented in teh most recent manual. The first is in the "Advanced", "CPU configuration" section. Set "MTRR" to "discrete". The second is in the "Chipset", "North Bridge Configuration", "Memory configuration" section. Set "Software memory hole" to "enabled".