Problem on RHEL4.7 mtrr

I've got a strange message in /var/log/messages :
"kernel: mtrr: type mismatch for d8000000,2000000 old: uncachable new: write-combining "

and when i look in the /proc/mtrr
I've got that :
"reg00: base=0xd0000000 (3328MB), size=196864MB: uncachable, count=1
reg01: base=0xe0000000 (3584MB), size=197120MB: uncachable, count=1 "

196864MB !!!! whaow !

how can i modify this ?

I had to look this up.
Linux Kernel Documentation :: mtrr.txt