P8P67 Overclocking questions.

[funkatation]

I just got a 2500-K and P8P67 and have been playing with the overclocking settings. I am trying to find out how high I can push it without increasing the voltage too much (if at all!). When I just change the multiplier (in this case, to 43), it seems the vcore will go past 1.3V when looking at CPU-Z. If I manually set the vcore to 1.240 it is still stable and never gets higher than that. The problem I see with the manual set vcore is that it always stays at 1.240 even when its idling at 1.6Ghz. When it was set to auto, it would go to .98 or lower. Any one have enough experience with this to know whats going on here?

Thanks!

 

[Arkainium]

As you have already noticed, if you manually set the vcore then the vcore doesn't change dynamically with EIST and C1E. You can use the offset feature to add to or subtract from the voltage specified by your VID (used when it's set to auto), which will preserve the voltage throttling at lower multipliers while giving you some control over the amount of voltage applied. It isn't perfect, but I think it's the only alternative.

 

[SlitheryDee]

I changed the offset on my board to -0.020 and it stays around 1.220-1.240 volts. For some reason mine would never go above 1.280 even when the offset was at the default setting, so you might have to use a larger number.

That tiny amount shaved nearly 10 degrees off my load temps, which were pretty high since I've got my rig in a relatively poorly ventilated HTPC case.

 

[Arkainium]

Something to keep in mind when you have EIST and C1E enabled is that unless you're using LLC, the voltage is actually higher than what you see in CPU-Z because turbo mode is only activated under load so what you're seeing in CPU-Z is the voltage with Vdroop. I don't know if this is important or not, but it's something I've been concerned about when seeing load voltages around 1.3 V.

 

[funkatation]

What I have been doing is keeping CPU-Z open while running Prime95 and seeing what the voltage gets up to, is this still not accurate for load testing?

edit: also I've messed with the - offset, it seems to be helping load voltages, but also looks like its lowering the voltage during idle as well... I am at -0.060 and in Prime95 I am at 1.272-1.264, I think it can go lower than that, I was stable at manual voltage around 1.240-1.245, but I don't want to make it unstable if while not in load its not getting enough voltage if that makes sense?

 

[Xed]

I've manually set my voltage and it drops to .964 or so when idling at 1.6ghz. Are you using the latest bios?

 

[StriperMike]

Take a look:

http://www.bit-tech.net/hardware/cpus/2011/01/07/how-to-overclock-the-intel-core-i5-2500k/1

 

[funkatation]

I'm using the latest non beta bios... are you using the beta bios?

 

[funkatation]

Also... CoreTemp shows a much different story on voltages than CPU-Z.. It has 1.224V in CPU-Z and CoreTemp will show 1.356!!!

 

[Arkainium]

I'm also using the latest non-beta bios.

Also... CoreTemp shows a much different story on voltages than CPU-Z.. It has 1.224V in CPU-Z and CoreTemp will show 1.356!!!

That's what I meant in my earlier post about seeing only the load voltage in CPU-Z when turbo kicks in. The value in Core Temp is the VID, and I think that's the actual voltage applied when set to auto (and the offset uses that as the base). So if you were to disable EIST and C1E, I think you'd see an idle voltage of around 1.35 in CPU-Z. I may be wrong though.

 

[Xed]

I'm using 1053 (the latest beta).

 

[Arkainium]

Anyone have any idea what "CPU Current Capability" does? The documentation is really vague. Is there any reason to ever change this from 100%?

 

[Zap]

edit: also I've messed with the - offset, it seems to be helping load voltages, but also looks like its lowering the voltage during idle as well... I am at -0.060

Wow, is that with the 43x multiplier?

I'm at 45x, but if I go below -0.005 or something like that, system gets unstable.

Anyone have any idea what "CPU Current Capability" does? The documentation is really vague. Is there any reason to ever change this from 100%?

100% means the board will not feed more than 100% TDP to the CPU (95W). Remember, Turbo mode only works within the TDP. You want it to Turbo higher, you gotta increase the current limit.

 

[Arkainium]

100% means the board will not feed more than 100% TDP to the CPU (95W). Remember, Turbo mode only works within the TDP. You want it to Turbo higher, you gotta increase the current limit.

I was wondering why my CPU never goes above 95W in CPUID Hardware Monitor (not sure how accurate it is). I'll try setting it to 110% to see if it makes a difference.

Also, see the "official" guide, which makes no mention of this option:
http://hardforum.com/showthread.php?t=1578110