I7-950 OC experience

[gizm0steve]

For a long time, I've only overclocked moderately. I'm a patient guy, but I usually only spend a day or two figuring out some incremental limit with a hair of over-voltaging. Always went with a cheap air cooler, nothing fancy. Up to this point I had only done pentium 4s and core 2s.
So last week I built a micro-ATX system: i7-950, Asus Rampage III, GTX 470, 12 GB memory, etc. Got a combo deal on newegg for a Corsair H50 water-cooler, so I thought I'd finally try water-cooling (albeit a beginner closed-loop). Like the reviews say it's a bit of a pain to install but I've fought worse battles.
The motherboard has a couple pre-made frequency profiles, so I tried the first one, 3.5something ghz. The temperatures were kissing 70-71c with prime95. That worked great, it was like night and day with Far Cry 2 and Civilization V compared to my old system (a core2 with 2x 8600GTS).
After playing games/working with that for about a week, I decided to try to push it a little more. The next premade profile (which the bios programmer felt was "crazy") has me at 3.874ghz. It's been perfectly stable so far to type in this post but running prime95 kicks the heat up to 85c+. (I turned it off after a few seconds.) 46-50c idle. All of the above are core temps, the cpu temp has a negative number, so I assume it's broken or speedfan just doesn't like it. My apartment is about 80F.
The case is Lian Li's little tower, I replaced one of the front fans with the radiator. (So there's the radiator/fan and another fan in the front, another on top, and an exhaust fan on the back.) The radiator had a couple fin dings in it, but they're pretty minor. It also has screwholes for a second fan on the other side.
So, there's a lot of new stuff going on here all at once for me. I was wondering if the temperature sounds normal for this kind of setup (small case, entry water-cooler). I was considering getting the second fan to stick onto the radiator but I'm not sure if that would help tremendously. Thanks in advance.

 

[delluser1]

Using the Asus overclocking generally sends your voltages skyrocketing.
Download CPU-Z and check the cpu voltage, just for reference, I use 1.18v to achieve a stable 3.8 on my 930.
Read some overclocking guide's, OC manually and you should be able to lower the temps some.

 

[gizm0steve]

you're right, i just assumed those default profiles left it alone. right now it's at 1.424v. i suppose there's never an easy way.

 

[gizm0steve]

Best answer selected by gizm0steve.

 

[MingtheMerciless]

Although Intel lists, Tcase = 67.9 C, it does not list Tjmax, temperature at the cores, though 100 C is thrown around because this is the point where CPU throttling kicks in. From what I have seen most people shoot for under 80 C.

http://www.pugetsystems.com/blog/2009/02/26/intel-core-i7-temperatures/

To control temperature hardware-wise, you can do the following (1) disable auto fan/pump control in BIOS to ensure the pump is acting at 100% (1400 RPMs), (2) use a Push-Pull configuration for your heat exchanging fans on the radiator, (3) reseat and reapply TIM (Thermal-Interface-Material), and (4) lapping the interface between the copper plate and processor. And of course, you could also get a more efficient cooling solution, on water or on-air.

Software wise you can reduce the base clock and voltage, but this is somewhat a trial and error process, to see how stable you can under volt while maintaining a certain frequency. As a general rule of thumb, changes in the base clock effect temperatures linearly, whereas changes in voltages effect temperatures quadratically. You should be able to modify these frequency settings in BIOS relatively easily, and there are probably some readily available guides online that will walk you through the process for your particular motherboard. From what I have seen and read, at voltage ~1.4 V, you should definitely be able to go beyond 4GHz. Meanwhile, at that frequency around 3.8GHz, you should be able to run stable with a lower voltage than 1.424V. For reference, on the i7-950 I have installed, I could obtain a stable frequency without any voltage changes at around 3.5 GHz, from there on I had to boost the voltages up to run stably. Also remember, that processor varies from lot to lot, along with your cooling solution, case, and etc.

 

[gizm0steve]

Just a little time tweaking it manually and I've been able to bring down the volts to 1.275 and still maintain 4.02 ghz for at least a half hour now, 80.0c max. I guess the motherboards have a ways to go with preset OCs. Thanks again guys.