3.8ghz 920 Crashing

[blu3skys]

Hey all,

im running an i7 920 at 3.8ghz currently, on a p6t (Non deluxe), 6gb ddr3 1333mhz g.Skill, and at the moment, when testing with prime95, i get crashes about 1/2 hr in, BSOD to be exact.

Currently i have changed the values of the following in the BIOS:
CPU Voltage: 1.31250
QPI: 1.4
IOH Voltage: 1.22
DRAM Bus: 1.56

Turbo mode is off, 20x Multiplier, 190 BCLK.

Help would be greatly appreciated.

 

[evongugg]

Ultimate Core i7 Overclocking Guide -- We Push Nehalem to its Limits

http://www.maximumpc.com/article/features/ultimate_core_i7_overclocking_guide_we_push_nehalem_its_limits

http://images.tweaktown.com/imagebank/Core%20i7%20920%20oc%204G%202008.12.12_(ENG).pdf

Intel Core i7-920 Overclocking Guide

http://www.xbitlabs.com/articles/cpu/display/core-i7-920-overclocking_3.html

 

[jay2tall]

How are your temps? What cooler do you have?

You could try setting your memeory to 1066 speed. Then test again. If it does NOT crash you know it is your memory and you should up your DRAM voltage to 1.6

If it fails again my guess is you have a C0 stepping 920 and will have to increase your vCore up a notch. I think your next step is 1.325. I have the same mobo as you.

 

[blu3skys]

Aha. Thanks. I have bumped up VCore a slight bit. No longer getting BSOD. However, now im getting freezes when i prime 95. So i have to do a hard reset. After some googling it said it has to do with the ram, maybe bumping up dimm voltages, or loosening the timings. THing is, for changing those settings it seems awfully complicated, and i was wondering if anyone could give me some advice.

 

[blu3skys]

Exact values are as follows
CPU Voltage: 1.325
CPU PLL: 1.84
QPI 1.33125
DRAM BUS: 1.54
Turbo off, BCLK Frequency 190

As above, I cant seem to find how to adjust ram timings and Speed. It should be in DRAM Timings but i cant seem to find.
Sorry, I'm fairly new to this, When you say DRAM voltage do you mean, DRAM bus, or QPI/DRAM voltage?

IDLE temps are at 34, 31 31 32, LOAD temps hit around the low 70s. Using a noctua NH-U12p

 

[blu3skys]

Found it. mY bad. but 1066 isnt accessible. it doesnt even show. Lowest was 1143, i selected that. Running prime 95 to test.

 

[jay2tall]

^ then run that, This is why you need OCed memory to overclock your CPU, it has to do with the memory divider. I'm suprised there is not a lower setting.

At the 1333 speed, I'd turn up your VDIMM to 1.6. 1.65 is the max and some memory moduals have it set to this in their XMP profiles right out of the bucket. Mine is 1.6v, I'd try that.

Sounds like you are making progress though.

 

[blu3skys]

Yep thanks. Definately making progress. So far no crashes. But while booting, i got a "Overclocking Failed, f1 to setup f2 for default values"
What exactly is this? I went into bios, and didnt change settings, and now its booting fine once again.

 

[jsc]

You may be on the ragged edge of what is doable for your particular chip.

 

[blu3skys]

Thatd really suck. What are normal temps for under load with prime?

 

[blu3skys]

Wow. The temps changed drastically. Still on 1.325 vcore, but for some reason idle temps are up 7-8 degrees. 41 idle on core 0. core 1 2 3, are 38 38 39 respectively

 

[gahleon]

Well it is funny that no one has given you the correct answer yet, but you're not even close to the right voltage. I am at 3.7 (3.885 with turbo burst). The C0 is a funny beast. I won't go further than that but I can tell you that you need to be at least 1.36 on the vcore. Whenever you are getting blue screens it generally means that your cpu doesn't have enough juice. There is what is called a vdroop when the processor is under a load. When it dips too much to do the operation you'll get a blue screen.

 

[drteeth]

as you know each processor is a bit different. I was running a CO step at 1.22 at 3.6 with Dark Knight and getting stable results. I got a second DO step CPU on exact same system setup (case and everything) and its stable at 3.8 at 1.19. Weird deal. Keep playing with it you will get there.

 

[blu3skys]

Wow. 1.19 at 3.8. Mines current 1.24 @ 3.7ghz. Ecstatic with this. Temps are peaking at 68. But the step up from 3.7 to 3.8 requires so much more power which is rather weird. I remember running at 1.35 for 3.8 and still getting crashes. I think i must have stuffed up ram timings and mhz.