my cpu is 800mhz(overclocked@840mhz). i have 1 x PC133 256mb ram, 1 x PC133 128mb ram and 1 x PC100 128mb. my question is, does the ram speed run in sync with cpu clock?(which is 140mhz) if not, should i carry on with this setup or better off withdraw the PC100 stick? thanks.

What is the model of motherboard ?? FSB ? xRatio ?? Does the MoBo support 133fsb ? can you lock the pci/agp bus ??

"does the ram speed run in sync with cpu clock?" That one stick of PC100 is forcing all your RAM to run at 100MHz. The minimal gain (40MHz) that you're getting by overclocking the FSB to 140MHz is being wiped out because the RAM is running 30% slower.

here are the specs : Gigabyte GA-6VXC7-4X 100/133mhz 6 x 133mhz(140mhz) yes i'm not sure about this...how do i check? jam, so, i would better off leave it with 384mb(133mhz) rather then having the extra 128mb(100mhz) that cripple my pc performance, right?

"i would better off leave it with 384mb(133mhz) rather then having the extra 128mb(100mhz) that cripple my pc performance, right?" It's a tough call. Ideally, you want your CPU & RAM running at the same bus speed, whether it's 133/133 or 140/140. You lose some performance by running 133/100 or 140/100...but you also lose by lowering your RAM amount to 384MB. I would try to come up with another stick of PC133 to replace the PC100. And make sure to tweak your BIOS settings. BTW, here's your board: http://www.gigabyte.com.tw/Products...

thanks for all the input. i have just remove the slower ram stick (PC100) and tried playing NFSU(40mins)...the loading speed seem to decrease...but smoother game play, probably due to the fact that its working at 140mhz??weird?!?! also, now i guess i know the reason why previously when i play NFSU the pc would reboot w/o any error message....lol