• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

Overclocking 400Mhz PIII ?

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

mooreswhat

Member
Joined
Apr 19, 2005
Hey everyone,

I was just looking at my friends old computer and we were wondering about the overclockabilty of it. Heres the basic stats:

Mobo= Pc Chips M756MLRT Socket 370 (Old Schoooool)

CPU= 400Mhz Pentium 3 running on 1.712 VOltS! (6.0 x 66.8Mhz)

I tried MBM5 on it but its not suported, do know any other motherboard monitor progrms it could use?

Also do you think it could get a small overclock? If so how much.

P.S. I'm not sure what speed ram it has all i know is there 128 mb


Thanks
 
It's a katmai processor. With stock voltage you could get 500-600mhz out of it, but I'd say anything over 500 is luck (unless you have a good cooler).
 
I<m not familiar with intel chips but im geussing that I would simply increase the FSB by increments of like 3 mhz until the cpu hits around 500 or becomes unstable? Maybe increase the voltage a little, but starting at 1.712 how high could i put it?
 
What kind of heatsink / fan is on the processor?

The basic idea is to do exactly what you said, and keep testing for stability with prime95. Your cooling with greatly affect how far you can go, and atleast the amount of voltage (with passive cooling I would'nt raise the voltage).

One thing to remember, is that the old motherboards did'nt have locked pci-buses. What this means, is that while you raise your fsb, the pci-buss will go out of spec. At some point it can corrupt your hardisk. Some motherboards will keep raising it from 66 to 99 and 100fsb to 132, and reset it at 100 and 133 (if the motherboard supports processors with fsb at these speeds.
 
400mhz PII's should be at 4 x 100. The only 400mhz processor that used the 66mhz bus would have been a Celeron back in those days. It couldn't be a PIII, as PIII's started at 450mhz.

Overclock wise, the 400 didn't have that much room. Blame it on the lack of lockable PCI/AGP bus, or what not. I couldn't usually get much more than 448 (4 x 112) out of them.
 
Socket 370? 66 FSB? Must be a Celeron. Voltage don't look right though. Was thinking the Cellies in that era were 2.0v default. Regardless, it all depends on whether the motherboard has adjustable FSB settings.
 
PC chips aren't good overclockers, the PC chips board I had (similar P3/cely) had an "auto-set" choice when it came to the CPU "pnp" settings. It basically means that you can select either "33" or "66" or "133" MHz, and the multipliers go up to like 12X in the BIOS. I didn't have much luck with PC chips, but you may have a significantly different BIOS...
 
You could try a prog called "softfsb" if the setup program doesn't let you o'c'.
It must be a celly, the last pentiums at 66fsb were klamath PII's, you probably have a katmai core. If it (the cpu) will let you drop the multi, then you could go for the 100mhz bus speed and drop the multi to 4...but 6*100 would probably be an unrealistic goal,but not unheard of here....Good luck
 
Back