can't (or duno how to) overclock my 1.6a

[CanisEstInVia]

Ok, the quirk about my setup is I have an mATX board. It's an Asus P4S333-M using the SIS645 chipset. It has a lot of overclocking abilities from what I can tell (cant do voltage bumping), but I can't get my chip to overclock above 1.8. My ram is a pc2100 256mb stick of Mushkin Performance ram. I ran the ram at 2:2:2:5 and it holds ok, so I think I have ok ram to be oc'ing with.

I took some pictures of what my bios looks like so you all can see and point out what I have to do.

Default
2133
2133 set <-------- won't run at this setting
cpu/pci frequency choices
cpu/memory ratio choices <------- also has ability to do 3:5
memory timings <--------- runs fine so far with this setting

I thought I read enough of this forum to figure out what to do, but my chip just won't oc. I'm sure it's a Northwood with the 512k cache so that rules out my having the slow p4 chip. Is it possible that my 1.6a just doesn't overclock well? From what I've read, I should be getting 2.2 with default voltage. Can someone please explain to me what to do to overclock my chip?

edit: temp reading in bios says my chip runs at 38 degrees Celsius, so my hs/f is set properly I believe.

 

[Bartman39]

I would back down on the memory timings (slowest possible) & bump the core voltage to 1.65 and then find the max speed and after that work up the memory timings...

 

[Duvie]

I agree always run lowest ram timings and settings at first until you see where the cpu starts to be limited...

Does the mobo overvolt naturally??? My p4s334 at deafult 1.5v would read 1.53v....How about yours???

Sometimes with some mobos from what I can tel...high mhz ddr can make you need to boost vcore of the cpu as welll...Don't ask me why....My 1.6@2.66ghz with 442mhz ddr needs as much vcore as my 1.6 does at 2.736 to run stabily...

If you run lowest setting and 1:1 ratio and you are still limited then it is likley the cpu...Also sis645 chipsets seem to have issues when running the higher fsbs...Many couldn't stability at any level above 140fsb, no matter the chip...

 

[CanisEstInVia]

Thanks you two for helping out this newb. Backing down the memory timing is all I needed.