Is PLL overvoltage safe?

[Sojuuk]

I am speaking of the internal PLL overvoltage option in my Asus z68 board. I can find tons of claims of what it can do, though not any of them can agree on it, but what I can't find is claims of safety. Will turning on this option damage my cpu much? How is it different than manually adjusting the PLL voltage? Please don't letmegooglethatforyou as trust me I have.

 

[ShuttleLuv]

PLL Overvoltage is different than PLL voltage. PLL overvoltage is practically a must for 4.8 and above (especially 5.0 to 5.1) on a Sandy. Another thing worth mentioning is the older stepping Sandy has trouble with PLL overvoltage enabled and will reboot or not boot, newer steppings and steppings are fine though. This was on older semi pre release models.

 

[Spare-Flair]

You mean internal PLL overvoltage? Different from CPU PLL Voltage (should be 1.9V max).

I have Internal PLL overvoltage on just in case but didn't need it for 5.0GHz.

 

[Falkentyne]

PLL overvoltage has something to do with skew of the pll voltage. You should ask Sin on XS or OCN about it. He said something like PLL overvoltage allows 500mv of the PLL voltage into the pll area, while usually it's 350mv. This is coming off faint memory.

 

[Forceman]

It is safe, but it could cause problems with S3 sleep. There should be BIOS updates to allow sleep with it on, but it depends on the board.

 

[Superfly3176]

Can someone explain what it does?

 

[Nickbaldwin86]

Can someone explain what it does?

https://www.google.com/search?aq=0&oq=pll+ove&sourceid=chrome&ie=UTF-8&q=pll+overvoltage

 

[ShuttleLuv]

You mean internal PLL overvoltage? Different from CPU PLL Voltage (should be 1.9V max).

I have Internal PLL overvoltage on just in case but didn't need it for 5.0GHz.

Lots of people have been running 2.0 and maybe even a tad higher since Jan '11 fine.

 

[Sojuuk]

thanks for the reassurances. I will have to tinker with it enabled when I get home and see if I can make that mysterious 5.0gigglehurtz

 

[Falkentyne]

"Internal" PLL Overvoltage is NOT the same as PLL voltage! Stop saying you have your PLL voltage at 2.0v so you can use internal PLL overvoltage...it's just not the same!

You could set your PLL voltage at 2.1v and STILL have your CPU unstable to post at 5 ghz without internal pll voltage enabled. This setting doesn't change the actual PLL voltage itself directly.

As I said above, it's some sort of skew with mV (in relation to the actual PLL voltage itself), sin0822 explained it (if I recall his name correctly) either on xtremesystems or on overclock.net. I only remember him mentioning something like 250mV vs 400mV or something...it's best off you just PM him if you want the details.

 

[Sojuuk]

I wish my bios would provide these sort of descriptions.

 

[Spare-Flair]

I wish my bios would provide these sort of descriptions.

In 30 years of CMOS based BIOSes, I don't think there has been a single BIOS that has been fully and properly descriptive instead of just barely cryptic.

I would also like a good "layman's terms" explanation of internal PLL voltage. I had a CPU die on me on Monday night and it was most likely a memory controller issue but I disabled internal PLL overvoltage just in case and won't be turning it back on until I have a better working understanding of just what this is.