i5 4670k with corsair vengeance pro 16gb 1600mhz CL9

there are dozens of good guides online for overclocking haswell cpus. some basics. (btw: overclocking haswell cpus is childishly simple, though i wouldn't just jump straight to 4.6, here is how i would do it)

1) reset your bios to stock settings (clr_cmos) this will reset your ram to it's SMP profile, not the xmp profile, which is what you'll need to do before you overclock and what Linus was talking about.

2) change your cache speed from auto to 3.3 or 3.5 (depending on what motherboard you have, basically the slowest setting there is)

3) change you cache voltage to 1.8V

Now we're going to take a small sneak peak at how good of an overclocker you have. this will help you dial it in faster

-turn your cpu multiplier to 45
-change your vcore to 1.25V

save your bios settings and exit the bios.

NOW - if your computer fails to boot into windows you'll probably never clock that cpu over 4.5ghz. frankly you'll probably be stuck in the 4.2-4.4 range in the end

If the pc boots into windows you can start to stress it with prime95 or occt, or IBT. if it bluescreens, or crashes or fails the stress test you'll need to bump vcore a little bit. download HWMonitor and keep an eye on temps, haswell cpus alter their clock speed faster then most monitoring software can keep up, so if it's thermal throttling you'll never know unless you watch the temps. at 90C haswell typically starts to thermal throttle. So if your cpu hits 90C and seems to never get hotter it's highly likely your cpu is throttling, you just can't see it. Stop the test and dial the vcore back a little bit. and try again

if it passes a stress test at 4.5ghz and 1.25V on the vcore without temp throttling you can bump the ghz up to 4.6, and try again. keep bumping the clock speed and stressing until the computer won't boot into windows or starts to fail stress tests. at which point you're at the end of your overclocking (mostly), it will just be a question of whether you can put enough vcore in the cpu at that ghz number to stabilize it without overheating and temp throttling when you stress test it. If you can, you can always try one more step up, but in my experience you only really get +1 on the multiplier at the most once you need to add vcore past 1.25V. typically temps and voltages will spiral out of control first.

there are two things that will limit you with a haswell, and only one of them is in your control.
1) temps - this is in your control. you can delid the chip to help, get a better cpu cooler, or alter the airflow in your case. if you're temp limited in your overclock then there is hope you can go further
2) luck - this is out of your control, every chip is different, some cpus are horrible overclockers. you'll know if delidding will help if you're having issues with temps, unfortunately if your cpu temps aren't breaking 70c and you blue screen no matter what voltage you set the cpu to, you've got a chip limitation, and you've hit the end of your overclocking.

basically the idea is this. around 1.25 haswell cpus start to get VERY hot. so if your cpu can't boot at 4.5ghz and 1.25V on the vcore you'll probably never see 4.5ghz or higher on that cpu. this can help you cut through the BS, and help you dial in your overclocking. Now then what do you do if you fail that quick test?

back the clock speed down without touching the vcore, until it WILL boot into windows. at that point you can start to stress test and playing with your vcore to your heart's pleasure. you'll probably have your overclock pinned down within 95% of the max possible overclock on that cpu in less then 2 hours. do a long stability test of your choice. Personally i like prime95 and 12+hours, but the choice is up to you.

Either way you should be good to go.

once you reach this point you can safely bump your ram back up to it's XMP numbers. do another stress test to make sure you're ok and presto!


BTW: don't get too discouraged if you don't have a great overclocker. on the whole most of the "average -to-poor" overclockers are the i5s... intel clearly binned the i7s to be better overclockers. it's not uncommon for i5-4670k to top out in the 4.0ghz-4.4ghz range.

Heck even in DC, my own i5-4690k topped out at 4.2ghz, and that's a refresh chip with better TIM and supposedly higher overclocking potential.

if you read what i just typed then you'll know the answer.

-yes- though just resetting your bios with a CLR_CMOS is enough. typically overclockers like to minimize all "other" issues when overclocking, and haswell is a bit sensitive to ram so it's solid advise, still stock settings for the ram after a CLR_CMOS is fine on it's own. You don't need to do more.

touch the frame of your case will ground you just fine. skin contact is all you need.

as for clr_cmos, if you tell me which motherboard you have i can tell you where to find it. as will your motherboard's instruction manual. in the bios there might even be a "reset to defaults" option which effectively does the same thing. depends on the motherboard.

depends on what cpu cooler you have.