Hi Jonathan. Below is the description for the MTRR (cut&paste from the xconfig description).
MTRR (Memory Type Range Register) support (MTRR) On Intel P6 family processors (Pentium Pro, Pentium II and later) the Memory Type Range Registers (MTRRs) may be used to control processor access to memory ranges. This is most useful if you have a video (VGA) card on a PCI or AGP bus. Enabling write-combining allows bus write transfers to be combined into a larger transfer before bursting over the PCI/AGP bus. This can increase performance of image write operations 2.5 times or more. Saying Y here creates a /proc/mtrr file which may be used to manipulate your processor's MTRRs. Typically the X server should use this. This code has a reasonably generic interface so that similar control registers on other processors can be easily supported as well: The Cyrix 6x86, 6x86MX and M II processors have Address Range Registers (ARRs) which provide a similar functionality to MTRRs. For these, the ARRs are used to emulate the MTRRs. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing write-combining. All of these processors are supported by this code and it makes sense to say Y here if you have one of them. Saying Y here also fixes a problem with buggy SMP BIOSes which only set the MTRRs for the boot CPU and not for the secondary CPUs. This can lead to all sorts of problems, so it's good to say Y here. Regards Frode On Mon, 2002-12-09 at 15:25, Jonathan Drews wrote: > Hi: > > Can anyone tell me what this warning means? > > (WW) System lacks support for changing MTRRs. > > > What are the MTRR's ? > > > > > Thanks > > Jonathan > > > _______________________________________________ > Newbie mailing list > [EMAIL PROTECTED] > *** To unsubscribe , or change message options, see: > http://XFree86.Org/mailman/listinfo/newbie _______________________________________________ Newbie mailing list [EMAIL PROTECTED] *** To unsubscribe , or change message options, see: http://XFree86.Org/mailman/listinfo/newbie
