Max Safe P4C and volts

[Richie]

Just wondering what the maximum you should put the core volts upto on a P4 2.6C chip ??

Currently running 3.25gig @ 1.625v (stock is 1.525) but its a tad unstable so I clocked it back down and am wondering what the maximum voltages I should use for this processor to get it stable at this speed....

[TiG]

I don't like pushing mine above 1.7v. I'm lucky in the fact i can run to 3gig at default volts with stable running (touch wood).

I'd say it depends on your cooling how far you should push it.

TiG

[Richie]

Oh I can get to 3.03gig on stock volts with the only changes I make being that I lock the PCI/AGP FSB speeds and its rock solid - encoded DVD for 6 continous hours which used 95% CPU and 56oC temps without a hiccup.....

Just that the 250FSB (1000FSB) is winking at me enticingly

[chrisf6969]

I've never found any increased stability over about 1.625, but then again I've always used aircooling. temps are more important. But even at cool temps above 1.7 is just heating up your chip and probably not going to help.

Usually what I do it set to 1.6v and see how high I can go and be happy with that on aircooling. This time I hit the motherboard limit so at 3.6Ghz I starting lowering the volts all the way down to default and it was still stable!

[Richie]

Do you think increasing the volts to the memory would help increase stability, bearing in mind the memory is not running any fater than it is when CPU at stock due to 5:4 ratio (250/200) when overclocked and 1:1 when standard (200/200)

[chrisf6969]

depends on the memory. Some memories like Geil like about 2.7-2.8 and Geil warranties it up to like 3.1v I think. I never volt my memory more than 2.8.

Right now mine is at 2.7v b/c Im only running at 300Mhz FSB + 2/3 ratio = 200Mhz (DDR400)

What stability problems are you having? change ratio to 2/3 with lax timings just so you know that its definitely the CPU limit.

Crank the FSB as high as you can go... I personally like running SuperPI (like to 8M places) and Hexus PI Fast for stability testing. Both give you errors pretty fast if the CPU is pushed too hard.

Once you know the CPU limit try a ratio closer to the memory's limits and then tighten up the timings until you have problems. Then go back to the last good timings.

[madwelshboy]

Hi chrisf6969,

What heatsink & fan are you using cos my setup is similar to yours, excellent oc by the way.

Just for your info too, my Geil PC4000's are rated upto 2.95v (unfort, our mb's can only hit 2.8 !?!), otherwise I'd be doing 1:1 @ like 275fsb :-(

[chrisf6969]

Vantec Aeroflow HSF