i7-3930k core voltage

[Akreontage]

Hi all!
Today I decided to overclock my 3930k a little bit. Nothing serious, just 4.2 Ghz. Mostly I was testing stability and lowering core voltage. The thing is, it somehow was stable at 1.210 (that was surprise for me), and then I tried to lower it even more. Of course it gave me BSOD with 1.205 voltage as soon as I started Prime95 test. No surprise. But then I went back to 1.210 and it gave me the same bsod... I started to increment voltage by 0.05 v but nothing changed (Even with 1.250 v). So then I loaded my default settings (3.8Ghz), and only then bsods disappeared. So now I set 4.2Ghz again and put 1.225 V... It runs Prime95 stable for 30 minutes now. It passed intel test. No problems. Can you explain me such behavior? Why haven't bsods gone until I loaded default config? Should I try to go with 1.210-1.220 again?

[HiVizMan]

When you messed with the voltages your OC became corrupted, the only thing you changed was the voltage. You did not redo the entire bios settings. You would not even have thought about doing that but it is something I tend to do all the time when OC'ing. OC fail go to bios F5 for default load up the last profile I had saved and start again.

[Akreontage]

HiVizMan wrote:
You would not even have thought about doing that but it is something I tend to do all the time when OC'ing. OC fail go to bios F5 for default load up the last profile I had saved and start again.

Thanks a lot! I didn't know that. I'll bear it in mind. Kinda don't understand it though but anyway...

Btw, Prime95 was running all night long with 1.22V. No errors occurred. I think it is very stable. And I've reached my ultimate goal - 59*C maximum temp on 4.2Ghz with fans not going full speed. It seems like it will run stable at 1.215V but I won't try it.

[HiVizMan]

That is not bad at all.

Let me try and explain what I very badly expressed.

When a OC fails, it can cause corruption accross the system. Lots of folks find their OS will not post again, or if they have RAID arrays the RAID fails. This corruption can happen even at the level of the bios and as you know there is data that is stored in the bios cache (lets call it that) and if that gets corrupted then the entire OC is messed up and not just the one setting that was changed.

Not sure if that makes things clearer. 🙂

[Akreontage]

Oh ok! I get it now. Your explanation will definitely reduce my headache in future. Thx a lot.

[Akreontage]

Today I managed to get 4.4Ghz with 1.290 vcore. Lowering vcore even more gave me bsods. 1.290V is very stable in tests. Just right now I ran short Prime95 test to double check stability. Everything is fine. Here are max temps:

Max temps are actually 60 on hottest cores after 8h test. Those max temp numbers you see on the screenshot are just the result of slow cooler acceleration :).
How do you thing, is it safe to use this oc 24/7?

[blackforce]

nice keep going.

[HiVizMan]

Looking very promising my friend.

[Akreontage]

I keep playing with my cpu, just to know what it's capable of. Today I tried to turn off HT. No, not permanently... Just to see what happens with temps and volts. First of all it seems like I can run 4.4 with HT off @ 1.270. It's too early to say, but 15 min prime test shows no errors so far. So it's more likely that it won't crash after hour and maybe stable after all as shows practice. And if not then my limit is 1.275. But The thing is... The temps are now higher than my last 4.4 oc with 1.290v and HT on. That confuses me a little bit because folks say that when they turn off HT they see dramatic temp lowering. And I see temp slight temp rising. :confused:

P.S. Sorry that I write all these questions in one place. Just don't wan't to spam forum with unnecessary topics.

[Zka17]

I think you're doing good... keep the CPU cores below 75C at max load and you're good to go for 24/7 use...

However, personally I don't like to use prime95, not anymore... you're just burning your CPU for very long hours and you won't get any benefit of that...

We have now ROG RealBench - it's much shorter in time and if it does two consecutive runs, then most likely your system (CPU and RAM part of it) are good to go...

And if your 24/7 usage includes gaming, don't forget to test separately the graphics settings too... nor the prime95 and ROG RealBench tests the graphics...