Martin MOKREJ� <[EMAIL PROTECTED]> writes: > Hi, > I have received no answer to my former question > (see http://marc.theaimsgroup.com/?l=linux-kernel&m=110827143716215&w=2).
That's because it's a BIOS problem. There are limits on how much Linux can work around BIOS breakage. > Although I've not re-tested this today again, it used to help a bit to > specify > mem=3548M to decrease memory used by linux (tested with AGP card plugged in, > when > bios reported 3556MB RAM only). > > I found that removing the AGP based videoc card and using an old PCI based > video card results in bios detecting 4072MB of RAM. But still, the machine was > slow. I've tried to "cat >| /proc/mtrr" to alter the memory settings, but the > result was only a partial speedup. > > I'm not sure how to convince linux kernel to run fast again. It's most likely a MTRR problem. Play more with them. > Finally, I put back two 512MB memory modules to have only 3GB RAM > physically, > and the result is at > http://www.natur.cuni.cz/~mmokrejs/tmp/128MB/only_phys_3GB/. The cheaper Intel chipsets don't support >4GB at all, and you always need some space below 4GB for PCI memory mappings/AGP aperture etc. > About a week ago I tried to contact ASUS, but no answer so far from their > techinical support through some web robot. > http://vip.asus.com/eservice/techmailstatus.aspx?ID=WTM200502111723398547 > I do not recommend their "greatest" and real "flag-ship" P4C800-E-Deluxe > motherboard for use with memory sizes above 3GB (although they claim 4GB > is possible). BIOS is the latest release 1.19, although 1.20.001 was tested > as well. In general non server boards tend to be not very well or not at all tested with a lot of memory ("a lot" is defined as >2GB for higher end desktop boards, or >1GB on very cheap desktop boards). That is a common problem on other motherboards too; Asus is not alone with this. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
