Aug 13, 2009
So I am very new to overclocking and am attempting a moderate overclock on my i7 920 - about 3.0-3.3 or so. I am trying to keep things simple so I have started by just upping my BCLK and voila, I am at 3.3, and am running prime95 with not too shabby temps considering the amount of OCing I plan to do (getting around 66 C core temps).

First question. Should I be concerned about any instability issues with leaving turbo mode on? As I understand it, the i7 may jack up my multiplier x1 or maybe even x2 if needed. I swear I have seen it jump up to x22 during prime95 but it's not doing it now.

Second question. I was surprised to learn that my BIOS will let me manually set my multiplier to x21. I have looked at a ton of different threads on this and I have not really seen a definitive response. Some people have speculated that it is just forcing turbo mode on all the time (possibly on all four cores). Out of all of the OCing guides I have read through, only one actually recommended changing this to x21 stating something about the CPU being more stable at x19 or x21 levels. All of the other guides seemed to gloss over the multiplier so I am guessing that maybe only certain boards allow this change.

I am running the ASRock x58 Extreme


Sep 29, 2009
You should include more info about your O/C Ie: cpu cooler / motherboard/ temps/ ect. As far as your questions go i think they are fairly simple. Turbo simply adds more processing power under load when needed, pulled from other cores that are not under full load, even with all cores under load it will top you up in a sense. If your going to stick with that oc and its stable and your temps are good, i see no reason why a turbo setting would hurt... but if you unstable at all then no. i am starting to see The multiplier can go to 21 ? great but do you need it! Sounds like a forced turbo. The big question is stability. I have been tweeking the I7 and come to realize that the tweeking is the fun and the result is really just a side note for everyday applications an I7 is not really in need of an overclock but your imagination and adventurous nature might be! I would set it to 3.20 to 3.50 and be happy as long as its stable. Hey but overclock the thing till the case melts around it if thats what turns you on! GOOD LUCK