What temp to stop stressing CPU oc?

[MacAttack]

I am just starting to OC my i7 860. I have it stable at 3.7GHz. However, under Prime95 the temps are about 70^ with occasional spikes up to 73^.

My question is at what temperature under stress do you call it quits and lower the OC?

 

[Kenmitch]

Most people would say your at that limit currently if you have a good cooler and good airflow in you case.

 

[MacAttack]

Thanks for the info. You confirmed what I thought I had read. 3.7GHz will be as far as I can OC this proc.

 

[Rubycon]

Improve cooling, lower frequency or reduce stress.

Those temperatures are nowhere near dangerous.

 

[MacAttack]

I tried moving to 3.8GHz, but it errors in Prime95 at 1.35V. I am not sure if I will be taking it to 3.8GHz. It all depends on how much time I have.

 

[imported_Shaq]

I wouldn't worry about temps when stress testing. It is only for a couple-few hours and nothing else will stress it that much. I ran LinX for 3 hours yesterday and it was at 84C the whole time. I then ran a few games and they rarely break 60C. And those are games that support quads--L4D,WIC,RE5,ETW etc.

Once you stress test you won't need to do it again for awhile at least. You may want to redo it every six months just to make sure it is still stable. There may be some migration in the interim and the OC may need to be lowered or the voltage raised. And if you upgrade every 2-3 years there will be little to no damage to the CPU. I believe they are engineered to last 10 years and OC'ing on air probably halves that life span at the most.

 

[JimmiG]

You can usually find the maximum allowed temperature somewhere on the net if you search around. Think it's 72C for your CPU, but I only did a quick search so I may be wrong. For AMD CPUs, it's usually lower, like 62C for my CPU.

I usually make sure my CPUs are below 55C full load.. Not sure why... but that's what I've done for the last ~10 years or so. Never had a CPU die on me.

 

[BonzaiDuck]

My two-cents may not be worth too much here. I haven't upgraded to I7 or I5 yet. But I checked the Intel specifications for the I7-800 LGA1156 cores. The TCASE-MAX at full-throttle 95W power is just shy of 73C.

From looking at the OP's and other posts here, it appears there are still sensors for the individual cores (he mentions "temps" plural) -- which may (or may not) exceed any given TCASE value. At one time, the rule-of-thumb was core temperatures about 10C above any given TCASE, but I had seen this vary (and even not reliably measurable with some Wolfdale cores).

So while Rubycon is probably correct (and who am I to talk -- for not having an I5 or I7 system?) that the temperatures are nowhere near "dangerous," I'd monitor the old legacy TCASE sensor at LinX or Linpack loads, and limit my over-clocking to just above TCASE = 70C with a room-ambient controlled at 80F degrees.

And that would be my scenario with a high-end heatpipe cooler like Megahalem. I probably wouldn't want the actual VCORE to exceed . . . something in the range 1.30 to 1.35V.

If I seem full of hot air, I haven't been to the forums for a few weeks, and just thought I'd sound off a bit.

 

[nyker96]

it's arbitrary but i say most intel hit a safty at 90C-100C so keep it around 70C or below seems reasonable. a friend had his at 80C linpack load seems to hold ok. but no one knows at what temp it will substantially shorten cpu life. these things are design for 10 year life span so got a leeways there. i say keep it under 70C if you want peace of mind.

 

[RussianSensation]

Intel's specification for current stepping of i7 860 is 72.7*C. However, I believe voltages rather than heat are more dangerous. My stock intel heatsink ran at 85-90*C at 100% load at 2.93ghz and the system never crashed!

Right now I artificially limited my overclock so that temperatures are <= 80*C. I am passing Prime95 at 72-75*C at 3.91ghz with 1.300V in the BIOS (1.296-1.312V in CPU-Z) under 100% load. My temperatures go to 77-79*C at 4.0ghz and it is stable at the same voltages. Trying to decide if I want to settle at 3.9 or 4.0. Beyond that, I need to increase my voltages a lot more. As I am finding out, Core i7 overclocking is almost entirely limited by cooling since the chips can do 4.5-4.7ghz with 1.5V+. But I am about 24/7 operation, not benchmarking records.

Also check what temperatures you get with the most intensive program you run. I run SETI at home which gets me 70-71*C (below Prime95).

Have you checked your temperature differences if you mount the Megahalems towards the top of the case vs. towards the back of the case fan? I don't have a top mounted fan so I shaved a good 5-6*C under load by directing it towards the back of the case fan. Yours may perform better directed @ the top case fan.