The i7-6700k is an utter waste of money, just get the non-K version. There is so little to be gained by overclocking a Skylake CPU, there's just no point. Overclocking Sandy Bridge CPUs made sense, the i7 2600k went from 3.4GHz to 5GHz often, 5.1GHz wasn't unheard of -- 50% gain in CPU frequency does translate to measurable and feelable (is that a word?) gain. But the i7-6700k can go to about 4.8GHz -- 20% tops but of course the CPU can turbo itself to 4.2GHz in many tasks so 14% typically. Now you are entering pointless territory, your real world gains will be vanishingly small.
An all-in-one liquid cooler will always be noisier than quality air cooling, for example the Noctua NH-D14. Especially in a great case like that. You'd need to build a very costly loop to have a quiet one and these days CPUs have dropped their TDP so much that there's absolutely no reason to liquid cool them. When you CrossFire/SLI and especially triple CF/SLI top video cards only then you need to begin to think because there's so little space between the cards for air to move. EKWB have special parts to help with watercooling such setups.
You should check the differences between K / non-K versions when it comes to virtualisation technologies.
My i7-4790K supports more stuff than the non-K version
(No idea how it looks in the 6000 series)
I've got a i7-2600K that's overclocked to 4.8GHz with liquid cooling. It's been running on that clockrate for about 3 years now with no issues, with stable temperatures.
Comments
The i7-6700k is an utter waste of money, just get the non-K version. There is so little to be gained by overclocking a Skylake CPU, there's just no point. Overclocking Sandy Bridge CPUs made sense, the i7 2600k went from 3.4GHz to 5GHz often, 5.1GHz wasn't unheard of -- 50% gain in CPU frequency does translate to measurable and feelable (is that a word?) gain. But the i7-6700k can go to about 4.8GHz -- 20% tops but of course the CPU can turbo itself to 4.2GHz in many tasks so 14% typically. Now you are entering pointless territory, your real world gains will be vanishingly small.
An all-in-one liquid cooler will always be noisier than quality air cooling, for example the Noctua NH-D14. Especially in a great case like that. You'd need to build a very costly loop to have a quiet one and these days CPUs have dropped their TDP so much that there's absolutely no reason to liquid cool them. When you CrossFire/SLI and especially triple CF/SLI top video cards only then you need to begin to think because there's so little space between the cards for air to move. EKWB have special parts to help with watercooling such setups.
The base and turbo frequency is different as well. Seems to amount to about a 10% difference in most CPU benchmarks, prior to overclocking.
tangible
I think "perceptible" would be closer to the desired meaning.
Noticeable
You should check the differences between K / non-K versions when it comes to virtualisation technologies. My i7-4790K supports more stuff than the non-K version (No idea how it looks in the 6000 series)
See http://ark.intel.com/compare/88196,88195 for yourself. There is no important difference besides what's necessary for overclocking.
Ironically in the i7-2600 days only the non-K supported VT-d.
I've got a i7-2600K that's overclocked to 4.8GHz with liquid cooling. It's been running on that clockrate for about 3 years now with no issues, with stable temperatures.