Just got a new i2600k and put it on a z68 asus MB. I've never overclocked before, but I thought I'd give it a whirl.
I started with the automatic options, but found out they weren't ideal and could lead to instability. So after many hours of reading these forums - I landed on setting the CPU ratios to 40 and left everything else at automatic.
I read that having the voltage at auto offset could lead to some voltage spikes, but being that I have the ratios bumped up only to 40, I don't think I'll have too high of voltage peaks.
I'm running my first stress test now (p95) and will check it when I get home from work. But my question is, when I took a look at the screen last - one of the cores was only under 50% load. It was actually jumping around a little 50 to 75 to 100% load and then back down. Is this normal?
I'm mainly just playing some games here and there and I'm not too concerned with extreme overclocking. Oh, also the temps were hovering in the mid to high 60s. Case is cooler master elite 335 and the cpu fan is a hyper 212.
I believe it is doing 8 threads. I didn't touch any setting other than selecting the default "blend" test. Just thought it was a little weird that the cores were all at 100% and then a few hours later one core had dropped to 50% (well, bouncing around anyway). Wasn't sure if that was a sign of instability or if that was a common sight to see.
The best thing I can say to you about OCing 32nm CPU is try not to go over the 1.4v mark with voltage overclocking I tried going above the 1.45 range on my i5 and well it hated me after that ;P but then again all CPU core are different none are identical in how well they will overclock. Just make sure you do stability tests after you reach your max OC otherwise you might end up with silent damage to your os and other software
CPU-z said it was around 1.28-1.29 at full load. I'm not sure if it spiked any higher. But I haven't touched the manual settings. It came with the auto setting on default and I just left it there. I realize it may be going a little bit higher than normal for only OC'ing to 4ghz - but I like how it automatically ramps up and down depending on how much cpu I need.
Let me explain more, I apologize, my internet was acting weird so was a short post. Stock vcore is .95v idling at 1.6ghz because of speedstep. It will go to up 1.2-1.25v during turbo. There are 2 modes when setting vcore, fixed and offset. Fixed will make it stay the same, offset will allow it to change like how it behaves at stock.
You can change llc and the offset value to get the vcore you want (stock idle but higher max vcore for a higher overclock). LLC at regular with an offset of zero should give you the same as stock. (I think there's not a 0 option so select -.005, I don't actually have a asus z68 but this is what I've read [I have asrock z68]). You could OC higher. LLC at medium with an offset of 0 should give you 1.3v (still .95v at idle as llc affects the max) and as I said earlier is 4.5ghz-ish. Of course you need to check what it actually is setting your vcore to and if you are stable at whatever vcore and multiplier you have set.
Alternatively you can try an undervolt with a negative offset value. I'm currently at a -0.02v stable and less volts mean less power and heat.
*LLC has vdroop implications and also voltage spikes and offset has a different base value for different companies. But this is just the simplest way I have found to explain to inexperienced OCers to get to 4.5ghz-ish as there isn't much performance increase higher that's worth the effort.
Every guide I've seen says to put it to extreme and most even say to turn off speedstep and c states among changing a lot of other settings but none of this really isn't necessary unless you're pushing the limits of your cpu. Really all you need to change is vcore and multiplier. I mention llc instead of additional turbo voltage (which does the same thing) because higher overclocks you will want it closer to extreme.
*Additional turbo voltage isn't the same as llc, I meant just changing the max volts without affecting idle.