Minimum vCore For 4.2GHz~4.5GHz Stability With Z68 & i7 2600k

Bint Box

Bint Box

Bint Box

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Hi,

I am just trying out some manual adjustments to overclock an i7 2600k CPU in ASUS P8Z68 Deluxe board and started of with an overclock of 4.2GHz using a base clock of 100MHz and a multiplier of 42 wth the vCore set to Auto and all of the DRAM settings also set to Auto. Using these settings the system was OK running Prime95 which I ran for 4 hours before turning it off.

The vCore voltage for the 4.2GHz overclock from the Auto setting in the BIOS was around 1.330v and the 4 core temperatures were maxed out at 62C, 65C, 66C and 61C.

I would like to be able to reduce the vCore manually for the 4.2GHz overclock but keep the system rock solid stable. At my 1st attempt at this I manually adjusted the vCore voltage to 1.12v but windows then failed to start. In the hope of having to avoid multiple resets and failed boots is there an acknowledged safe minimum vCore level that I should start from.

If the system runs at stock speeds the automatic value for the vCore voltage is around 1.240v when running Prime95.

Thx for any advice
 
Adam123 said:
Start at 1.330v and work ur way back? Until It fails prime.

I'm gona oc my 2600k next week n thats what i will be doing.
Click to expand...


Thx for the quick reply and the suggestion. It is obvious now you have pointed it out to start high and back it off to a lower value rather than my dumb idea of starting low to try to get it operational.


To go back to settings for overclocking, do most people leave the DRAM settings on auto in the BIOS for 4.2GHz to 4.5GHz or do they have to be then manually tweaked with voltage adjustments etc?

I would just like to find out if I can achieve a stable overclock without having to do anything other than increase the multiplier, ie, leave everything on auto except the base clock on manual at (100MHz) and multiplier on manual at (42 or 45)

Thx
Bintos
 
Every chip is different with Sandy, you may even have a real stinker of a chip that needs +1.35v for 4.5ghz, or you may have a real beauty of a chip that needs less than 1.3v for 4.5ghz.

As above start out at around 1.35v and dial it back until unstable, don't forget adjusting LLC, phase, duty and CPU capability may also help with a nice low voltage.
 
go in at 1.36V or 1.35 as above and work down till you get unstable Some chips will do well others won't.

My chip is happy as larry at 1.323V but others have been lucky to drop below 1.3 and remain stable
 
Thx for the replies, currently I am running Prime at 4.2GHz with a vCore of 1.30v (55mins test). My next step is to increase the multiplier to 45 and let the vCore voltage auto adjust itself then I will start backing the vCore down bit by bit.

To go back to the DRAM settings, do I need to do anything with them or just leave them all on auto, the RAM is 1600MHz GSkill?


Thx
Bintos
 
Leaving at auto is pretty much what I did to begin with, tested at Auto with my desired multiplier, stressed it and checked how much voltage was being used, then used that as a base line to work down from.

Auto voltage will usually over compensate, especially on Asus boards. So if it shows something daft like 1.4v for 4.5ghz don't be alarmed. Auto voltage tried to pump 1.58v through my chip for 5.3ghz, when infact it required 1.44v.
 
Dissapointing news :(, I increased the multiplier to 45 keeping the bus clock at 100 to get 4.5GHz and it BSOD'd when running Prime after a couple of minutes. These were the only adjustments I had made, I let the vCore autoselect itself and did not make any changes to any other settings other than the multiplier. Before it crashed i had a quick check at the vCore value and it was around 1.36v

It seems to run rock solid stable at 4.2GHz but with only the multiplier changed to 45 for 4.5GHz it crashes Prime in minutes :mad:

Have I just been unlucky and got a pig of a CPU or is there anything I can do to try to get 4.5GHz stable? I can live with 4.2GHz stable but 4.5GHz would be nice........:cool:


Thx
Bintos
 
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