I have been attempting a stable overclock for my 2500k chip. So far I have been stable (wont say my system is stable yet) with a fixed voltage @ 1.33 and LLC 2 (25%). I ran my system on voltage = auto and it averaged @ 1.38v. Went back into the bios and changed to offset -.050, and worked on it to -.040. With this offset everything appeared stable, but my voltage was hovering around 1.33 and spiking to 1.38 at times. How often this happened I cannot say, Prime95 blend test ran while I was sleeping and this was the max number shown. As soon as I stopped Prime I got a BSOD, so I know I need to increase the voltage if I wish to keep using offset.
I decided to try offset just for the simple fact I dont use my computer ~16 hrs a day, but with needing to up the voltage again (because at idle i drop to < .91v which caused the BSOD after I stopped prime) is spiking over 1.38v worth it? Is there any way to tell this technology that is smarter than me to never drop below 1.xxx volts?
What is your motherboard make and model? Are there any 'load line calibration' settings to mess with? The offset voltage setting really is the way to go. Otherwise you're dumping needless excessive voltage all the time into your CPU. It took me a bit of tweaking, but I'm very happy that I got mine stable using the offset voltage.
Asrock z77 extreme4. I have LLC options of 1-5 (5=100%). When I originally started everything I read said to change LLC to 3 (50%) which worked for the most part but where LLC 3 failed me when I started lowering my initial 1.35v, LLC 2 has worked great. LLC 4/5 seemed to shoot way to much into the CPU. LLC 3/4/5 kept giving me the same issues with undervolting while in idle.
I had an issue with LLC, as well, where it wouldn't give enough juice at a moderate load. You kinda have to compromise with the offset voltage. I kept my LLC where it was but bumped up my vcore just one notch and it all smoothed out. I notice my vcore will 'spike' up to about 1.38 volts, too every now and again, but, at least in my case, when it spikes up this high it's literally mere moments. I've even wondered if it isn't just an erroneous software reading , honestly. Unless you notice it staying there for longer than a few seconds I wouldn't really worry about it. There are people that run their 2500/2600K's at 1.38 volts 24/7, and even then they don't die IMMEDIATELY (of course I wouldn't recommend doing that; just saying that short spikes up that high for very short moments of time shouldn't hurt anything in my opinion).
Saw it at 1.38 for more than a few seconds, so my first thought was shut down Prime, which caused a BSOD when the CPU dropped into idle. So I have to raise my voltage which is now going to cause it to spike higher than 1.38v. If I am spiking at 1.39 or worse even 1.40, whats the point when I can fix it at 1.328?
Well I can't tell you why your particular machine is behaving oddly, because that IS odd behavior. I've never heard of that happening so profoundly. Sounds like you can:
1.) Do like you said and just set a fixed voltage. You're pumping that voltage into your CPU all the time, but it's not like 1.33 volts is CRAZY high or anything. Or:
2.) You lower the LLC and raise your vcore offset. It won't spike your voltage so high, but obviously when your're running your CPU at full tilt the voltage will be higher than it needs to be.
I would recommend doing number two first and monitoring your voltages while doing things. Get a feel for where the voltage normally sits, how high it goes, how long it stays there, etc. If you determine that you like the voltages then keep it there. If you don't, then set fixed. Other than a little bit of increased heat, thus a slightly shorter life expectancy, there really isn't a a HUGE disadvantage to setting a fixed voltage.
You can also try to get a hold of someone at ASRock, because that's not normal behavior. Not sure if that would be worth the effort, though.
And as always, if someone else has any idea of a setting to tweak that might fix this issue, I'd be curious to hear it. I know of none, however.
If I am understanding this correctly, my additional turbo voltage is set to [Auto]. I have speedstep disabled (which im good with) and thats why my system idles at 1600 and goes straight to 4500 (which was another question I had in a previous post). If I change my offset to lowest voltage setting so I do not BSOD during idle, I should be able to dial down my turbo voltage to prevent the spikes, and run lower voltage over all while @ 4.5ghz. This should let me set the idle voltage to whatever it has to be, and then adjust the voltage when using turbo to 1.328 (so far my fixed sweet spot). Does that make any sense, or seem possible?
Saw this part of the guide and made me think of your problem. Do you have everything set as follows?
C States are the main functions of a CPU. Below is an image describing each C State.
C1E does not affect any normal overclock. It can somtimes affect an extreme overclock like 6GHz. Don't change this setting. The other C states can cause you to BSOD when idling when using Offset VCore mode. You shouldn't BSOD if you are using Fixed VCore mode.
So heres your 2 options:
Offset Mode: Your CPU will use VERY LITTLE voltage and speed when idling, ANYTIME you idle. (Even browsing can be considered idling.)
Enhanced Halt State (C1E): Enabled
CPU C3 State Support: Disabled
CPU C6 State Support: Disabled
Package C State Support: Disabled
Fixed Mode: Your CPU will run full voltage and speed all the time, even when idling.
Enhanced Halt State (C1E): Enabled
CPU C3 State Support: Enabled
CPU C6 State Support: Enabled
Package C State Support: Auto