4790K overclock - time to stop?

aisle9 · January 31, 2016

I'm running an i7-4790K at 4.6 GHz with a vCore of 1.235 (reported as 1.236 in HWMonitor and CPU-Z). My cooler is a Cryorig H7. The absolute highest peak temperature I'm comfortable with is 85C, with typical load temps in the mid to upper 70's. This is a $300 chip, after all. I'm not willing to play fast and loose like I was with my G3258. First off, here's my methodology for OC'ing:

Spoiler

1. Once multiplier is set, run three Cinebench benchmarks in a row.
2. If it passes those, run three POV-Ray benchmarks in a row.
3. In a now-removed portion of the test, run a small FFTs test for about five minutes in Prime95 to get an idea of the absolute max temperatures. On my Pentium, these would top out around 85C at 1.35v. On my i7, these instantly shot to 96-99C. Like, within seconds of starting the test, prompting thermal throttling, an end to the test roughly four seconds in, then a five-minute idle for the PC before a ten-minute timeout. Never using that test again.
4. If it passes steps one and two, run two RealBench benchmarks back to back.
5. If it passes, run 15 minutes on Intel XTU.
6. If it passes, run five RealBench benchmarks back to back.
7. If it passes, run a RealBench stress test for 15 minutes.
8. If it passes, run AIDA64 for 15 minutes.
9. If it passes, run OCCT for 15 minutes.

If it passes everything and temperatures stay in check, bump up the multiplier. If it fails but temperatures are good, up the voltage by .02-.05, depending on temps. If it fails and temperatures are maxed, dial the multiplier back. If it passes but temperatures are as high as I'm willing to go, the sweet spot has been found, and I move into more strenuous testing:

1. Ten RealBench benchmarks in a row
2. One hour of Intel XTU
3. One hour of AIDA64
4. One hour of OCCT
5. One hour of RealBench
6. Six hours of OCCT (most of my overclocks fail this--I've even had stock setups fail at this step)
7. Regardless of whether or not step 5 passed, four hours of Intel XTU
8. Four hours of AIDA64
9. Eight hours of the RealBench stress test

If it passes all of those steps (step 6 is optional, assuming it survives the hour of OCCT and passes everything else), I'll call it stable.

This OC did fail the OCCT test, but because I ran it overnight, I don't know exactly how far in it got. Presumably at least an hour, because it had already passed that mark. I haven't run steps 7, 8 or 9 yet, but I think I've hit my ideal OC. Here are a few images, also spoilered for space, to show where I was after some key benchmarks:

Spoiler

HW Monitor and AIDA64 readouts after one hour of AIDA64:

HWMonitor and RealTemp readouts after four hours of Intel XTU:

I'm not sure where the 4.7GHz is coming from. I've never seen it break 4.6GHz during actual use.

As you can see, I don't have much headroom left on temperature. I do plan to do some media editing on this machine, mostly Photoshop and SoundForge, with the occasional video mixed in, but I'd like a rock-solid stable setup when doing that, and may well just go back to stock for things like that. Given that, are there any tricks with the 4790K that could get me to a stable 4.7 for gaming, like VCCIN adjustments, system agent and I/O offsets like existed for the G3258, or is it just generally considered a good idea not to screw around with those? I've tried 4.7 as high as 1.26v and might have been stable, but temperatures during the first RealBench stress test broke my magic number of 85C. The world may never know!

Thanks for any help!

Belgarionbg · January 31, 2016

Mine is rock-solid with this settings

For stable 4.7 wants at least 1.28 and I don`t find it reasonable to push it more.

aisle9 · February 1, 2016

1 hour ago, Belgarionbg said:

Mine is rock-solid with this settings

For stable 4.7 wants at least 1.28 and I don`t find it reasonable to push it more.

You're running a better cooler than me, but I feel compelled to ask anyway: what type of temps are you getting at load during stress tests? If it's right at 85C, I might just add another SP fan to the backside of my H7 to buy myself those couple of degrees and bump the voltage up. That's if I can get my CPU stable at 4.6 GHz at or below 85C.

Belgarionbg · February 1, 2016

Around 87-89*C at full load when testing with prime95. And yes, I`m talking about the warm seasons when my delta room temp is no less than ~27-30*C.

And believe me, it`s get really hot especially in the summer.

But now in the winter this is what I get.

I have changed the original Noctua 120mm with Noctua NF-F12 PWM to get control on the rpm`s.

Because of the stupid control on my second cpu fan header I switched the original 120mm noctua as back fan to case fan header 1 together with the 140mm Noctua through splitter and I set the header control to follow the change in cpu temp and to ramp rpm`s alongside with the pwm noctua. That save me from buying other pwm fans.

TLDR; currently my fans are spinning around 400-600rpm and don`t change speed until the cpu goes over 70*C.

Separately I have one 120mm FD (front) and 140mmFD (top) fans which are connected to controllers - also set on ~500rpm.

In the end the pc is near death silent in 90% of the time.