Originally Posted by The Sandman
I agree 100%. You'll need more than a H100i to get 4.8+ nicely stabilized.
I've seen a few posts claiming H100i at this level but from what I've personally witnessed with my 1236 bin chip it isn't very likely unless you live in the arctic,
or have a rare chip and a very loud rig due to crazy high fan rpm's.
Check my sig rig, I know what it takes to cool a 8350.
All my OC's are 24 hr prime95 stable, IBT AVX max for 20 runs, and a bunch more. Look around there aren't to many able to prove this claim.
It's not easy but definitely can be done, I just have very strong doubts about the H100i running much of a long term stability test at this level.
Before I start into this, I want say up front that in no way am I trying to represent an AIO closed loop system like an H100 to be on the same level as a custom loop.
When I had FSB at 250, I was able to do some 20 pass IBT AVX runs at 4.8 and 3 plus hours of Prime 95. Granted that's not 24 hours. During these runs, temps were in the low 60s IIRC with Vcore up at 1.525V.
In your case you would be able to achieve the same results with much lower temps. I believe we have the same bin chip.
What's changed now in my case is the RAM is moved from 1600MHz Snipers to 2400MHz TridentX, and FSB running at 300MHz. I have yet to profile this thoroughly, but I have done some IBT AVX runs. It's possible the extra strain on IMC may make this version of the system less stable. I'm pretty sure the CPU-NB and HT Bus are running at 2700MHz now which is the highest I've ever been able to run. I could back those down a notch if they turn out to cause problems, but I won't hide the fact that I want that CPU-NB interface to run as fast as it can.
I can probably be talked into attempting 20 pass of IBT AVX or a few hours of Prime, but I don't think I have the patience to go a full 24 hours.
Also want to respond to the crazy high fan rpm comment. My H100i has four fans capable of 2600RPMs. The fan profile I use will spin them to max at 60C. So yes a bit on the loud side considering when I do the bench runs I have the side panels off. I don't know if this is the best thermal scenario, but my thinking was I wanted to make sure the air getting into the radiator was room temperature and not in any way warmed up by internal components.
So to sum this up, with the hardware I have, goal is to solve for CPU temp of around 60C and see what the fastest stable run is. I believe 4.8 is there or very close with the thermal target in mind.
Also to the best of my knowledge, the system has never crashed due to CPU running at this speed. This also includes a significant amount of time playing CoD Ghost, which has to be the most severe application I've ever ran. I say this because not only is the CPU maxed for all 8 cores, the GPUs are also saturated as is the RAM. The game has memory leaks up the wazoo. System was stable for all the time played, although I won't play the game further until I see IW fix their game, assuming they are capable of doing it.
BTW, I do hope your rig can push past 5.0GHz.