Is the hyper 212 evo enough for overclocking my i5 4690k?



is the cooler master seidon 120m enough?
 
A lot of it depends on your ambient air temps, within reason the 212 evo is a good enough cooler to replace the stock and allow mild overclocking maybe 4.2 to 4.4ghz. A better air cooler or dual radiator aio like an h100i would allow for a max overclock. Not a big fan of aio's, they're expensive, tend to be noisy, problematic in terms of air in the lines, failing pumps etc. Just more headache than it's worth when a decent air cooler will get the job done. Much of it may depend on your particular chip (cpu lottery), 4.5 to 4.7ghz tend to be the upper end for most chips. Core voltage becomes a faster limitation than thermal throttling, they simply can only overclock so far. Unless you're into competitive overclocking and willing to really push the voltage and take the risks going past 1.4v on vcore etc.

My particular cpu I think is around average for oc abilities. Running 1.28v on vcore it's stable at 4.6ghz with uncore at x42 and xmp turned on for the ram. I could run it at 4.2ghz at around 1.18v to 1.2v, 4.4 at around 1.2 to 1.22 etc. I've reached 4.7 and temps are safe but to get from 4.6 to 4.7 means pushing from 1.28 to 1.35 or so on vcore. That's a big leap in core voltage for an extra 100mhz which is why I backed it off for daily use. A sign of the chip reaching it's physical limits. No amount of extra water cooling is going to make much difference in this case, cool or not pushing that much voltage to the cpu isn't a good idea. Most people agree the upper limits of 'safe' is around 1.4 for vcore and personally I'm not comfortable running it 24/7 over 1.3v.

For the same price, the cryorig h7 holyrage mentioned is a slightly better performing cooler with a better designed mounting system and is designed to avoid any ram clearance issues. Similar in design to the 212 evo just more refined and polished. The raijintek themis evo is another good cooler in the similar price range. If you wanted to expand your budget to around $45-50 there's the slightly bigger h5 universal from cryorig or the phanteks tc12dx.

If not going with a 240mm radiator I wouldn't bother at all with aio coolers. They just don't perform much if any better than decent air cooling. When water cooling became popular it was due to performance of real water cooling with custom loops made of capable parts. A large enough radiator etc. Most inexpensive aio coolers jumped on the bandwagon and in an attempt to make it affordable went with the lowest common denominator for parts and mass produced non serviceable units riding on the popularity of entirely different setups. Just my .02 but I wouldn't waste time or money on an h55, h80, h80i or other pricey underwhelming aio's.