P4C OCing - Vcore & Vdimm??

[shredisn@tdead]

OK, so now I've got my mojo working, how do I crank it up higher? The 2.6Ghz P4C is ROCK SOLID at 255, 1:1, 3.34GHz (see this LINK for a Sandra b/mark) and all I've done so far is up the Vcore to 1.675 or thereabout.

When you guys said OCing the P4C is easy you were soooo right! I'm absolutely amazed how easy it is to achieve DDR500/1000FSB, looks like you just need some decent memory - the ADATA PC4000 sticks ROCK.

BUT, how do I take it further? I can get it to 263 by taking the Vcore up and Vdimm up but it's not 100% stable and I don't really know what I'm doing now so have backed down to 255... Remember we're trying to get to 275 here!

So, pardon me for asking but here's yet more noob Q's...

• How do you know if you need to up Vcore or Vdimm when you hit an unstable bus speed?
• What are safe limits for Vcore & Vdimm before the kit fries - is it really only heat limited?
• At what temps should I start getting worried?
• Do you want fries with that?

Maybe I should run that program to test the max speed of the RAM, memtest memset or something, right?

[Mr Meltdown]

You are at max sensible vcore already. Vdimm can be cranked as high as it will go, if you have 3.0v available then use it.

If you want to know the max CPU ability then you will need to remove the ram from the equation by dropping the divider ratio to 5:4 (CPU 250 MEM 200 etc) and then using sensible Vcore on the CPU crank the CPU FSB up in 5Mhz increments until it won't POST anymore. (POSTing ability remember)

Reset BIOS and you now know the upper limit of your CPU. It won't run WIndows like that, but at least you know.

Now then, now that you know what the CPU can do, then you repeat the above with the mem ratio @ 1:1 again.

You can then play around with CAS timings etc after all that. But you need to establish what your CPU and then you Memory can do 1st really, then you can fart about with the oter stuff.

Cheers,

MM

[shredisn@tdead]

Originally posted by Mr Meltdown
using sensible Vcore on the CPU crank the CPU FSB up in 5Mhz increments until it won't POST anymore. (POSTing ability remember)

Cheers, MM. So "sensible" means lower than 1.675; set it to default maybe?

Got any good CAS timing links so I know in what order to play around with which timings?

[Mr Meltdown]

Have a look on mobo specific forums is best bet. Try here: http://forum.oc-forums.com/vb/forumd...e=30&forumid=4

Cheers,

MM

[chrisf6969]

you're probably close to the limit already. With air cooling and a good chip the best you can really hope for it 3.4Ghz and you're practically there. The problem is its so easy to get to where you are... you want more.

Lower your memory ratio and slow crank up the FSB and then run PiFast. That always gives me that fastest indication of the CPU stability.

I bet when you change your memory ratio and make the timings better you get close to the same memory score anyway.

[Axion]

whm what mobo?

if its an abit then your not gonna get higher than 255fsb 1:1 stable because of a bios issue...

your gonna have to go 5:4...