i7920 @4.0GHz(2.66GHz stock)
OCZ pc3 15000@1910MHz 10/10/10/28 1.65V
Top power 800 bronze
Basically, all I changed in the BIOS is
BCLK 191 *21 = 4.01GHz CPU
191*10 = 1910MHz RAM
CPU voltage 1.325V
I read that the QPI/vttt needs to be roughly equal to the CPU voltage but changing the voltage to as little as two steps above the auto setting resulted in continuous computer power cycles which I have to hit reset to stop. With the settings the way they are, I left prime95 running for approx 8 hours and when I went to bed it was still running with max core temp of 79 degrees C with no errors. When I woke up this morning, my computer had restarted but the BIOS did not revert back to default settings so I am guessing it was not catastrophic shutdown. I am not sure how much longer the test ran for but I figure that for everyday use 4.0GHz might be ok or I may revert back to 3.8GHz and see if the test lasts longer.
Did I miss anything that should have been changed? Would you be happy with my results?
Antec 620 hydro cooler. At 3.8GHz I can reduce the CPU voltage to 1.3V and my core temp after running prime95 for 30 minutes peeks at 72 degrees C. Also, it is core 0 that peeked at 79. While I was watching the core temp, core 0 would jump between 77 and 78. The other cores were anywhere between 75-77 degrees C. At 3.8GHz core 0 would peek at 72 but was staying steady at 70-71 the other cores were in the 68-70 range. I have the 12mm fan mounted on the back case with the radiator mounted in front of the fan. The fan is pulling cool air from outside the case and pushing it through the radiator into the case. I have an additional 4 side mounted fans blowing outside air onto the mother board and two exhaust fans. One on the top of the case and one in the front.
I am not disputing that my temps are hot. I would like to see day to day operating a lot cooler than 79 degrees. CoreTemp defaults to turn the colour of the temperature yellow at 80 degrees C and red at 100 degrees C which further backs up what the article states. I Played Crysis 2 for a couple of hours and my core temp did not go above 61 degrees C. I also ran 3dmark11 repeatedly while tweeking my GPU's and my core temp did not go above 61 degrees. I will definately keep an eye on core temps but I am more concerned with figuring out if there are any other settings that I failed to change.
I tried applying more thermal paste as well as reseating the the pump. I tried a 2nd fan in push pull but It is in the way if the hinge for the side door so that is not happening. I thought about another fan on the outside of the case on the rear but according to the article it will at best only add 1 or 2 degrees more cooling so I scrapped that idea. Antec advertises this cooler will keep an i7 980X @ 3.3GHz at 100% load at approx 66 degrees C. Not sure if full load they used is as torturing as prime95 but I am running an i7 920 @ 4.0GHz which is 1.34GHz over the stock speed and it is running on average 10-12 degrees hotter than the 980X @ 3.3GHz. I am starting to think that maybe this temp is normal and nothing to really worry about. I have a stock air cooler that came off an i7 960 and i was running in the mid 70's overclocked to only 3.36GHz which happens to be the stock speed of the i7 960. From what I have seen air cooling is really only good for stock speed up to a moderate overclock. It really doesn't compete with a hydro cooler. Thanks for trying, though.
Also forgot to mention that with CPU running at 3.36GHz core temp hit 65 running prime95
To me it really sounds like a heatsink contact problem, you may have applied too much thermal paste or maybe that particular chip runs hot. I have my i5-760 overclocked to 4.0GHz and prime95 does not cause my CPU to go over 76 degrees. 75 was my cutoff, but it did occasionally bump up to 76, but not for too long, which I was fine with.
I have never actually overclocked a 960, but I would assume it would be quite similar to my 760, being the same architecture and all.
Sorry for the confusion with all the numbers I threw at you but it is the i7 920 I am overclocking. What cooler do you use? There is apparently a difference in the temps with identical systems using different hydro coolers. Also, your i5 760 at stock speed I believe is 2.8GHz and mine is 2.66. Mine needs to work a little bit harder to hit 4.0GHz. Another thing I noticed is that your i5 runs at 95W vs 125W for i7 920 which may also account for the slightly hotter temps. Again, I am not sure if my temps are above the norm for my setup. I am hoping to hear from someone who has overclocked this particular series of processors using a water cooler to similar speeds but I appreciate any feedback at all.
Ah you are right, I thought the 920 was 95W like my 760, so both of what you said probably do play a role in your higher temps. I am using a Corsair H60. Not sure how my cooler compares to yours.
How are your case fans configured and how is your cable management in your case? Sometimes those can have an effect on heat if you dont have enough airflow through the case. Not a huge amount, but even a few degrees can really make a difference.
No H60 here http://www.overclockersclub.com/reviews/antec_kuhler_h2... but they have an H50 and an H70. Looks like the H50 is worse and the H70 is better than mine so I guess ours are probably equal. Cables are neatly run and tye wrapped where possible. The four 12mm fans on the side all blow outside air onto the motherboard while the top and front fan both exhaust. My case is a cooler masterstacker 830. It's big with lot's of airflow.
That is a really nice case, even though im not a huge fan of top-mounted PSUs. Anyway, I dont see an airflow problem.
Back to the original issue of getting it stable at 4.0GHz, have you tried dropping your ratio back to 20 and increasing your BCLK? I know it will make you completely redo your overclock settings, but when i was overclocking my processor I just couldnt get it stable with a 21 ratio, but I reworked it with 20 and found a stable point.
Thanks. I like the case too. The nice thing about the top mount PSU in this case is the PSU can be mounted with the fan facing up to draw outside air in rather than from the case. Back to the temperature issue, I downloaded a hardware monitor and noticed that the CPU fan is staying at the base speed of 1450 RPM even though the temp is increasing. The smart fan control is enabled in the BIOS so I guess I will have to troubleshoot on Sunday when I get back from visting family this weekend. I also never thought to lower the multiplier with a higher BCLK. I will give it a try on Sunday also and update sometime around Monday evening with my results. I ordered a 12GB triple channel Patriot Viper extreme ddr3 2000MHz kit from newegg this morning so raising the BCLK is also going to allow me to run the RAM at stock speed and still OC the CPU. Thanks for the tip!
It turns out the fan speed that was showing was the pump and the fan runs at a continuous 2000rpm. I scaled the overclock back to 3.8 GHz since 4.0 seems to be a bit unstable. Also, I installed a 2nd 2000rpm fan for a push/pull configuration and after running prime95 for 12 hours my peak core temp was 68 degrees C. Think I will leave well enough alone and stick with 3.8GHz.
Good deal. The difference between the two clocks is so minimal you wont really notice a difference, but at least you know you can get it to 4.0. I have always though it was crazy how after a certain OC point the temperatures just shoot up. Anyway, glad to help. Cheers!