At mild overclock (4.5GHz) I went into the BIOS before any testing and got the red screen warning about overclock problems. So, after booting up after the red screen I ran Intel Burn Test for a quick look and it failed. After a ton of reading and looking at voltages I lowered the PLL slightly from the 1.8V nominal and then was able to pass IBT. (no further testing yet as I had some torrents to seed). From what I understand CPU PLL is one of those mysterious things that no one short of an EE degree knows much about, either raising or lowering might produce a stable clock. Does that pretty well sum it up, so is my adjustment smoke and mirrors or a valid step? Are you wanting some information on CPU PLL, or are you just asking if it's normal that lower can help?
Untested: other Win7/Vista/XP. What PLL definition files are supplied with setPLL? A command-like window will popup in the background. Can get rid of the popup window with one of two ways. Disable User Access Control (UAC) in Control Panel or ii. Aug 12, 2007 - ClockGen will show, in its main window, available functions on your system depending on your system specifications. “PLL Control” and “PLL.
Haha, yes, it's normal that lower can help! I often suggest this to users, especially on newer boards as it's generally set too high by auto these days. If you want info about what CPU PLL does, let me know and I can link you to some information about it.No, I don't need any specific info other than verification that this is a normal tweak, as I said I couldn't find much info about it. I had read a bunch of old posts here and there where people were talking about radically increasing that voltage, and a few probably more relevant to Sandy Bridge that suggested the adjustment may go either way, up or down. I'm not especially paranoid about blowing anything up, I just have a lot to learn. OK, yes it's completely normal!
Increasing CPU PLL was only necessary in older boards like P45 or earlier, since X58 and above it's not really needed, nor does it often help to raise it, actually the opposite as stock seems to be a bit high usually. P45 or below = raise helps stability and increase could help increase OC X58 and above = lower to start, stock is often too high, going above stock value rarely helps at all, does not tend to affect OC at all unless it's too high and then it brings instability. OK, yes it's completely normal! Increasing CPU PLL was only necessary in older boards like P45 or earlier, since X58 and above it's not really needed, nor does it often help to raise it, actually the opposite as stock seems to be a bit high usually.
P45 or below = raise helps stability and increase could help increase OC X58 and above = lower to start, stock is often too high, going above stock value rarely helps at all, does not tend to affect OC at all unless it's too high and then it brings instability.Thanks! Sorry about slow replies-been pretty busy around here. I just wanted to confirm that lowering the CPU PLL voltage on my GA-Z68XP-UD4 (revision 1.3) board definitely helped improved stability. Specifically passing 12 hours of Prime95. For the world of me I couldn't pass 12 hours of Prime with CPU PLL voltage set at auto or manually setting it to 1.80v After reading a lot of overclocking related posts on the Gigabyte Z68 boards I decided to start playing with the CPU PLL voltage.
I started at 1.70v and slowly worked forwards and backwards from there. I seem to have found a sweet spot at 1.76v set in BIOS. Now I'm solid as a rock in all apps, games and can even pass 12 hours of Prime95:) I also noticed on BIOS F6 that VCCSA is auto set slightly below the Intel 'recommended' value. Mine auto set at.920v - Intel says.925 so that is where I manually set mine. Gigabyte GA-Z68XP-UD4 Intel i7 2700K G.Skill DDR3 16Gb 1866Mhz eVGA GTX 570 SC Corsair HX1000 H20 Swiftech/XSPC Last edited by wevsspot63; at 10:52 PM.
ClockGen is an program dedicated to overclocking. Its main purpose is to change the system clocks on the fly: FSB (Front Side Bus) and GSB (Graphic Side Bus).
ClockGen also provides some functions that allow you to improve and monitor your overclock. ClockGen is an program dedicated to overclocking. Its main purpose is to change the system clocks on the fly: FSB (Front Side Bus) and GSB (Graphic Side Bus). ClockGen also provides some functions that allow you to improve and monitor your overclock. If your mainboard does not appear in the list or if you can't open your system, you can try to guess the clock generator family with the chipset.
Most PLL models are dedicated to a chipset, and knowing the chipset may help to figure out the PLL model family, especially on ICS chips. On ICS chips with a 6 figures name, the model consists in the 4 first figures.
For example, the ICS 954148 belongs to the 9541XX family. The following table may help you figuring out what PLL family your system uses. Windows 98, Windows 98 SE, Windows Me. Windows NT (SP4), Windows 2000, Windows XP Home/Professional, Windows XP 64, Windows Vista, Windows Server.