All I did to get my setup to 3.8 (3.9 or 4 with turbo) is to up the BLCK to 160 or so. I didn't have to mess with voltages other then setting my RAM to 1.65. I made sure the "uncore" was within .5 volts of the RAM voltage (1.21 or so) which is also about what the CPU voltage is @ stock.
I'm using a Scythe Mugen R2 in a NZXT Phantom, and my temps will max around 70 degrees under heavy stress with HT on. I don't hit more then 55 during heavy gaming though, so it's okay for me. I'd like lower temps, but I think I'd have to change coolers for that.
with the i7's you most likely won't have to increase voltages for an overclock like that, of course it depends on your motherboard (yours is very good) and the heatsink/fan (also good)
With my "cheap" Asus p6t motherboard I got my i7-930 completely stable at 3.5GHz while undervolting to 1.1375v (in BIOS), load temps with a Coolermaster Hyper 212+ push-pull just barely exceed 60C in Prime95 according to RealTemp (around 58 according to HWMonitor)
HT enabled, i'm pretty sure turbo got it 3.8-3.9
Maybe you'll have to manually set the voltages. I believe 1.21 or so is the stock setting (on my board anyway) and that voltage was good for up to 3.8 GHZ. I think the "uncore" was default to 1.23 or so.
I've been running stable at 4.0 (200 blck and multiplier limited) with 1.25v or so. I had it at 4.2 and was stable in Prime95 (temps in the mid to upper 70s) but gaming was unstable. My temps with 4.0 GHZ are upper 30s-mid 40s idle and 55 or so during gaming.
Oh yeah, I have HT off as it adds quite a bit of heat at 4 GHZ and up....
After seeing your voltages I'd say your QPI/DRAM voltage is way too high. I thought it should be very close to CPU. You should read up on that.
So right now I'm running:
QPI/DRAM: 1.237V --> Auto had mine way too high as well...
IOH PCI: 1.508
DRAM BUS: 1.654
I have the multiplier set to 21, with HT and Turbo off. I have the power saving on, so the CPU changes between 12-21 multiplier. This puts my memory @ 1603 MHZ with timings of 7-8-7-20 if I remember correctly.
This gives me a max CPU of 4.2 GHZ and I just finished several hours of Fallout New Vegas with my CF 5850's @ 825/1100 without issue.
I think I saw my CPU max @ 55 degrees and the GPUs max @ 66 degrees. I think when I had this setting with HT on i was in the mid 70's for temps during Prime 95.
Nobody can tell you the "exact value" you need to set your system to. You'll need to experiment and see what works for your system.
I'm running an Asus Rampage 3 Formula.
I think you should decrease the QPI/Dram voltage a little.
Have you read up on overclocking an i7 yet?
not yet, once i have read chucks guide to OC.
I was worried abt the OC coz my stock temps are too high, OC will increase it so still haven't tried OC.
can you plz tell me what QPI/Dram core voltage exactly does ? shud i keep it 1.2500V ? the existing is 1.37500V.
Yea reaper667 i decided to overclock this morning.
I have an i7 950 and same mobo. The problem I found when i set my settings it restarted my whole bios to default setting my AHCI hdd to ide and not letting me boot to windows worth a check. Other thing try going default seeing if that boots up if it does must be with your settings.
Hows your temps btw?
Im hitting 4.2ghz @ 1.32 (dont remember the exact number.) with the h50 temps havent gone past 80C.
oh and btw some ram voltages dont need to be as high as 1.65, i ran memtest86+ for about 6 hours as well, no errors at 1.56 6-8-6-24 CR1 1600mhz.
My core temp is at 31 C and 75 C under max load with the 4.5ghz now the settings are still the same but my QPI volt is now set to 1.50625 running stable at moment ran heavy load for a hour and no blue screen yet
dang your qpi is alot high than mine. Whats your vcore for on your cpu. Oh and btw I ran my first OC for an hour and it was stable and decided to run it longer late noticed most oc settings would crash between 2-5hrs. i ran for 12hours on the settings I have no crash.
i think the max "safe" volts for each i think intel has is 1.4 i try to stay under that but if its work for you gj!