Overclocking a PIII 667EB

[jdelmund]

Hi,

I currently have a PIII 667EB and an AZZA mainboard and PC133 128 RAM. i'm planning to change the mainboard to an ASUS P3V4X for overclocking. Is this still possible? Have i hit the ceiling here since the FSB is already running at 133mhz, or can i wring out more from my p3 667???

Thanks.
jdelmund

 

[Ulysses]

You are probably pretty near the max FSB the 667/133 will do. Most overclockers get 700/100's, or similar, and then shoot for 900/133 or better. I don't think it would be worth it to get another board if the AZZA is performing OK, although that ASUS is a good one.

Your chances are a little better if your P3 is from the cB0 stepping. If that is the case then the 667 should have one of these s-spec #'s on it: SL453, SL3XL, SL45X, or SL3XW. If not, then it is a cA2, which is generally not as good as an overclocker.

Generally you need to overclock about 10% to notice a significant difference and that is not very likely with the 667, since 133 MHz +10% = 147 MHz, which is very high.

 

[jdelmund]

how can i determine if it has cb0 stepping, or see the spec #s???

>Your chances are a little better if your P3 is from the cB0 stepping. If that >is the case then the 667 should have one of these s-spec #'s on it: SL453, >SL3XL, SL45X, or SL3XW. If not, then it is a cA2, which is generally not as >good as an overclocker.

what do you mean by "very high" at 147Mhz, meaning the motherboard will not do this particular bus speed? doesn't the p3v4x have a frequency up to 166 Mhz? is it possible if i do 5.0 x 160Mhz or something higher than 133mhz?

>Generally you need to overclock about 10% to notice a significant difference >and that is not very likely with the 667, since 133 MHz +10% = 147 MHz, which >is very high.

 

[jdelmund]

Also, what has the CPU stepping have to do with OC'ing?

 

[Ulysses]

If you look on the CPU itself or on the top of the black plastic cartridge or on the outside of the Intel retail box, you should see some code numbers and letters. At least one 5-character series of these should begin with "SL" and that is the S-Spec. If the spec for a P3 667 is one of those I mentioned then the CPU is a cB0, otherwise not.

The cB0 stepping has been found to overclock better than the earlier steppings, so overclockers prefer them.

Generally speaking, most P3's will not run stably at much more than 133 MHz, no matter what the speed or stepping. That is why overclockers get those designed for the 100 MHz bus - they hope to increase the bus to 133 MHz. But your 667 is already there, so you can't expect to go much higher with the CPU, even if the RAM or the motherboard are stable at much higher speeds.