Ok problems with Overclocking and video card

[jediphx]

Ok I have an AXIA 1 gig T-bird, Epox 8K7A, Globalwin CAK38 and 256megs Crucial DDR PC2100

I have set all the jumpers on the mobo to default. I have two video cards, a Matrox G550 32 meg DDR AGP and a Hercules Prophet II MX 32 meg AGP

Both have a fan on them.

Overclocked to 10x120=1200 CPU temp 100F under load
Overclocked to 10x 130=1300 CPU temp 103F under load

Also at 1200 running the Prime95 Torture test the cpu runs at 106F

Now at 1200 all games run fine and 3dmark2000 completes

Now at 1300 programs run fine but using the Matrox or the Hercules 3dmark2000 starts to have graphical glitches and then hard locks. With fan on the heatsinks of thevideo cards the heatsink is cool to the touch. In the bios I really dont see anywhere to set the pci and agp bus divider like my old BX board so i have no idea what its at. One thing I do notice that if I lower agp 4x to agp 2x even without the heatsink on the video cards I get no lockups at all but lose like 600 point in 3dmark. Can anyone help me out here? Im still new to the AMD side of things. Thx

 

[fwupow]

Your MB was designed to run a 100 or 133 front side bus. So it should automatically switch to a lower divisor at 133MHz. The problem may be that you have set your FSB speed to 130 and since the MB is still using the 1/3 divisor your AGP is running at 86.7MHz. If you increase your FSB to 133, your MB should switch to the 1/4 divisor and drop your AGP speed down to 66.7MHz, which is the proper speed for AGP. If you leave your cpu multiplier at 10x, you'll of course have a cpu speed of 1330MHz.

The 1/3 and 1/4 divisors actually refer to the PCI speed, so with an FSB speed of 100MHz the PCI runs at 1/3 or 33MHz, while the AGP runs at double this speed or 66MHz.

I may be wrong about some of this. I don't have a source of info about your specific MB and how it determines it's PCI/AGP speeds.