How to Overclock an i7-2600K on and ASUS P8Z68-V LX motherboard

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Weaksauce
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Through a lot of reading, I have found that there isn't much information on the particular BIOS of this board. Working toward a viable OC with this board has been a pain, so I'm going to make it easier for others (noobs like myself) that may have this setup.

You'll need to have your BIOS updated and if you'd like, TurboV EVO from ASUS updated and installed. Also having CPU-Z and CoreTemp or RealTemp helps a lot. Prime95 and IBT also for stressing.

My current OC is x46, 100mhz, and a voltage of 1.295v.

Getting to these settings, the learning curve, wasn't very much fun.

After you get the multiplier unlocked in the BIOS and have the BCLK adjustable, you are still stuck with "offset" for VCore. Here is how that works and I'll post my BIOS settings in the next post.

The voltage offset doesn't show up until you disable EPU in the BIOS. Also, there really isn't a setting for VCore. It's just this odd, arbitrary CPU Voltage number. But once you start working with it, it's all relative.

Anyway, the voltage number shown in the BIOS is what the CPU is currently at, including offset. This number also shows up in TurboV EVO in manual mode after CPU Voltage.

I set my multiplier at x46 and BCLK at 100 and left it there. Additionally, the multiplier didn't unlock in the BIOS until I "unlocked" it in TurboV. I'm sure it was just a setting the software changed, so when I list my BIOS settings hopefully these settings will be available for you.

To adjust this offset, you move it up and down. When I started my OC, the BIOS had my CPU voltage at 1.2ish. I put the offset to .080, saved, and booted, ran Prime95 blend. Core Voltage in CPU-Z bounced .008 as it does a lot, but the top end for VCore was 1.312. You can also see the VCORE in TurboV. Monitor-Sensor. The VCore and Core Voltage in CPUZ match.

Neither are your CPU Voltage.

Those settings crashed, so back to the BIOS. BIOS had my voltage at 1.245. I moved my offset to .100, saved, booted, tested. VCore was 1.336(top of bounce) on load and crashed. Into the BIOS, voltage read 1.265, which is good because I had moved the offset .020. Moved the offset to .110, saved, booted, tested (vcore 1.352), crashed. Booted to BIOS, voltage read 1.275, added .010 again to .120 offset, saved, booted, tested (vcore 1.360) crashed. And so it goes.

I kept this process going until I got to 1.295. The reading after the last crash was 1.285, and I adjusted my offset to .130. Saved and ran all the tests and was able to run Prime 95 for an hour on blend then an hour on large as my previous setting was good on blend but failed in large. After that progress, opened IBT and was able to run standard with a high temp of 81* then ran again on VERY HIGH with a high temp of 83*. My high running Prime95 was 76*.

I opened TurboV, and sure enough it shows my CPU Voltage at 1.295. The VCore in the sensor bounces as the chip uses less power for browsing etc. This is normal. If you ever need to find out what your VCore is, just fire up Prime 95 for a few seconds. Your CPU voltage is listed in TurboV.

You can save profiles in TurboV, and they work while you are in Windows, but I couldn't get the adjustments to save into the BIOS. You can play with them and check stability without having to reboot, but in order to have the computer boot into your overclock, you'll need to save the settings in the BIOS. At least this is my experience.

Thanks for reading. Any questions, just ask. I'm going to reboot and mark down my BIOS settings and put it into the next post.
 
Settings:
ASUS P8Z68
i7-2600K
G.Skill Value 1333 8GB RAM
Onchip video

AI TWEAKER:

OC Tuner: Manual
BCLK: 100.0
Turbo Ratio: By All Cores
By All Cores: 46
PLL Overvolts: Auto
Mem Freq: Auto
I GPU Max: 1650 (I never touched this)
OC TUner-----> DO NOT TOUCH. It starts Auto-OC
DRAM: All Auto
CPU Power Management:
CPU Ratio: Auto
SpeedStep: Enabled
Turbo: Enabled
Auto for everything else

CPU Offset sign: +
CPU Voltage (1.295 for me): .130 (Shows your current voltage and the offset that is bringing the CPU to that value)

The next is a + and everything else is AUTO

ADVANCED TAB

CPU Ratio: Auto
Adapt Thermal: Enable
HyperThread: Enable
Active Cores: All
Limit CPUID Max: Disable
Disable Bit: Enable
Virtualization: Disable (I don't know why)
Speed Step: Enable
Turbo: Enable
C1E: Auto
C3: Auto
C6: Enable

There it is. Can I OC it higher? Possibly. But it's stable now and all of my limited attempts at the 47 multi have failed. Plus, going from 4.6 to 4.7 doesn't impress me as much as going from 3.4 to 4.6. :)

I hope this helps someone. Good luck!
 
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the Asus support forums have lots of information on BIOS OC settings (particularly the ROG forums). The Asus Z68 EFI BIOSes are mostly the same between models.

ALL 2600K cpus are capable of hitting at least 4.8Ghz with good motherboard, adequate cooling and voltage bumps. You should be able to squeeze some more Mhz out of your chip. It's easier to find your max limit if you use fixed voltage instead of offset. Once you know how high you can go, experiment with the offset.

The AI sensor utilities are not accurate and tend to lag. Stick with RealTemp instead. I only use the AI utility for Fan Control
 
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Thanks for that.

I wrote this because there is so little information on this board in particular. The BIOS is hamstrung in that it only lets you use offset to move the CPU voltage up and down. At least as far as I have found in the forty hours I've spent messing with this.

Most folks that are planning a big overclock are going to buy a more overclockable board.

I can move the cpu voltage up and down in the TurboV. But this doesn't save to the BIOS from what I can tell. As in my other thread, I would boot, then go into TurboV and load the profile I had saved with my settings then apply them. With what I have written above, I've figured out how to get those settings into the BIOS so I don't have to muck around with the profile stuff when I boot up. I can just start doing stuff. I'm sure others have figured it out also, but googling for it has turned up nil. Plenty of stuff for the PRO version of the board, but the BIOS' aren't exactly the same. If they were, I could have been done with this last week.

Now that I know what I'm doing (sort of), I could experiment with it, but I like where it is and 200mhz isn't going to get my rendering done that much faster for the guaranteed additional heat it would generate. For someone with the same setup, I totally encourage them to raise the roof on it.
 
Thanks for the info on overclocking this board. I just finished a new build and can't wait to see what I can get my i5 2500k to. Hopefully I can apply these settings to my cpu though its not an i7. :)
 
Aratech said:
Thanks for the info on overclocking this board. I just finished a new build and can't wait to see what I can get my i5 2500k to. Hopefully I can apply these settings to my cpu though its not an i7. :)
Click to expand...

No luck. :(

I followed every step and when it reboots I'm at 3347mhz or something like that from the stock 3300mhz. Not sure what Im doing wrong.
 
Sorry Aratech.... I may have left a few things out. I replied in your post, but I'll also put it here for anyone future-googling how to OC with this board..

The only thing I left out of this guide, and I should edit it but it's semi-selfexplanatory, is that you need the newest BIOS and you definitely need the newest TurboV. I installed the TurboV utility off the disk and it wouldn't let me OC at all either.

I updated the BIOS and the AI Tweaker/TurboV utility on ASUS's site. And don't use the "over the network" BIOS update because those settings never got to ASUS's site. It just sits there.

Go to ASUS's site and download the BIOS for your board. Then you can update FROM FILE on your hard drive.

If you have done all that, and really it's not hard to do just some downloading really, then I'm not sure what isn't working for you.

Though I can tell you I wasn't able to do anything, like you, until I updated the Tweaker and the BIOS. AND I wasn't able to move the multiplier at all until I "unlocked" it in the tweaker. I'm assuming my BIOS settings reflect that now, as the tweaker would have changed the BIOS to show a movable MULTI.

AND, when you are changing the voltage and the Multi in the BIOS, you have to type it in and hit ENTER. Then you have to save of course.

Finally, lastly, when you have the BIOS and Tweaker/Turbo up and running on the newest, there is a tab in the tweaker that is a one-button OC button. Reset your BIOS to defaults, then open the tweaker, and let it run it's own OC. It'll turn on and off and on and off as it tries different settings and checks stability. Just keep a paper and pencil around so you can write down the settings it's trying. It'll keep going, find stability, then ask if you want to go any higher. You can either save right there, with your new OC, or let it keep going.

Either way, you'll come up with a ball park figure. For my auto-OC on my 2600k it wanted to do a x43 and 103BCLK. It was stable, but I couldn't figure out the VCORE. Now that I know more, I suppose I could go retry it. But when I tried Prime95, within a few passes my heat was in the 80's C. I think the auto OC just feeds it way too much voltage so it gets too hot. Plus 43x103 isn't 46x100.

I really hope that helps. Any other questions, just shoot
 
This is so helpful... you are right my friend when you say that there is low to none info about OC a p8z68 motherboard from ASUS...

thanks! will try it soon!
 
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