i7 4770k undervolting, weird problem

[pepeo]

hello everyone

i am trying to undervolt my 4770k, since the stock voltage was too high (1.192V) and was causing extremely high temperatures with my noctua NH U12P SE2, around 83-85C with 33C ambiemt temperature

so i manually set the core voltage at 1.00V on bios, and ran intel burn for about 4 hours and got much better temperatures, something like 68-72C, and no errors, blue screens or something like that, so i think it is stable, but i will be doing some more tests later

but the problem is, i dont want the CPU to be at 1V all the time, so i read about adaptative voltage settings. my motherboard is a gigabyte z87x ud3h, and it doesnt have this setting on bios. to solve this, i downloaded intel extreme tuning utility and set the core voltage at 1V and adaptative voltage, but there is the problem, when i run any stress test or game, the voltage wont lock at 1V maximum, but something like 1.136V

is there anything that i am doing wrong?

thanks for the help

 

[CrazyTeeka]

the voltage wont lock at 1V maximum, but something like 1.136V

Take a look at page 46 - http://download.gigabyte.eu/FileList/Manual/mb_manual_ga-z87x-ud3h_e.pdf

CPU VRIN Loadline Calibration is what you need to experiment with, try it on high then turbo then extreme and see how each one effects the Vcore.

What this bios option does is force the VRMs to do stricter voltage control.

 

[MikeyTen4]

Hi Pepeo

I've recently OC'ed the same CPU, but on an Asus Z87-Plus. For the record, I had a look at Intel XTU and abandoned it since I got strange things going on too. Some readings it gave didn't match other monitoring tools, or what my bios was telling me. At stock settings the max voltage and stuff on my 4770K was through the roof according to XTU! I'm not sure if it was reporting false figures, or if it was forcing things to go beyond what I'd told them to (i.e. like your voltage here), but either way, it just seemed like it shouldn't be trusted to me. Strange considering it's produced by Intel, but there you go. Also, the general consensus of OC'ing via an application like this or Asus AI Suite as opposed to doing it in bios seems to be that it's never as reliable, and after my own experiences I have to agree.

Then again it might be the specific tests you're using - some stress tests use 'AVX' instructions, which allow the CPU to draw more voltage than you've told it to. What you want to do is run stress tests that don't utilise AVX instructions. I went through this whole thing myself, and after asking about the relevance of AXV tests and reading up I came to the conclusion that so few applications use AVX instructions in a day to day environment that it's not worth trying to find an OC that's stable long term while using AVX. The difference in temps between good, 'standard' stress tests, and those using AVX instructions was phenomenal on my machine. In fact, they often meant the difference between stable and not stable.

Some important points I discovered were...
- DON'T stress test a Haswell CPU with Prime95. Due to AVX apparently.
- Aida64 is the only Haswell certified stress testing utility at present, and you can run tests and choose whether to include AVX instructions or not.
- OCCT is another good stress testing utility which allows you to disregard AVX.
- Good monitoring tools include HWiNFO, CoreTemp, RealTemp, and HWMonitor.
- The TJMAX on the 4770K is 100c... personally I aim for no higher than 90c absolute peak at full long term load during a long test (i.e. 12 hours or more). Then I try to tweak it to get that temp down.
- It's worth using varied core ratios on the different cores if you're struggling, just to get that bit more out of your CPU. I'm running mine at 4.4GHz on 3 cores, or 4.3GHz with all 4 cores in use, with adaptive voltage, max voltage 1.28, and my highest temp under long term full load is about 88c. At constant long term full load it typically floats at around 85c. My idel temps, with adaptive voltage clocking it down, are about 25c-30c.

Bear in mind, in the real world, you'll NEVER have your machine running at full load, on all cores, for hours on end - i.e. playing games, video editing, audio processing, etc.

I hope that helps a bit (sorry if I told you things you already know!).