CPU Overheating During Prime 95 Test

[CoronaBlue]

I built a new computer two days ago. In it I installed an Intel i5 4670K at stock speeds, and a Noctua NH-L9i aftermarket cooler (as well as the thermal compound that comes with it).

 

Last night I began stress testing to check for any errors. I ran Prime 95's small FFT and used RealTemp GT to monitor my core temps. The results were pretty bad. Two of the cores hit 99 degrees Celsius after only eight minutes.

 

My first thought was that the thermal compound had been applied incorrectly. The NH-L9i is difficult (at least for me) to simply stick on and screw in. The first go round it did slide a little bit while I was inserting the screws, and I don't think the compound was completely centered to begin with. So this morning I opened my computer up and reapplied the compound. I was much more careful this time (the pea sized dot was completely centered) and attaching the fan was much less of a hassle.

 

That said, my temperatures are still a bit high. I did notice some much improved idle temperatures. Each core idles at around 30 degrees Celsius, and they are all within one or two degrees of one another. When running the same small FFT my first three cores hit 97 degrees Celsius in the time that I tested them. Mind you, it wasn't as drastic, and they seemed to stabilize at around 95 degrees Celsius. What really gets me is that the fourth core, even after 30 tests, was stable at around 85 degrees Celsius. 

 

I ran 30 tests over a period of 14 minutes. I can only guess at the ambient temperature in the room. The thermostat for the central air and heat says 21 degrees Celsius, but it is down the hall from the room with the computer, which is known to vary from the temperature of the house.

 

I know that the NH-L9i is not really made for overclocking (at least according to a benchmark that I read), but I thought that it would do a fine job at stock speeds. I've also read that fourth gen Intel processors just run very hot. I'm not sure if it matters, but Prime 95 said that my CPU was an "Unknown Intel".

 

Please note that I have applied thermal compound a grand total of two times in my life (this is the second computer I've built, if that clarifies it a bit more), and I am VERY new to the whole stress testing thing. At this point I just wanted to see what people who have a lot of experience with this sort of thing think about my specific situation.

 

Thanks so much in advance.

[flibberdipper]

NEVER run Prime95 on Haswell. As I remember, it can really fuck your day up.

[Tea1337]

NEVER run Prime95 on Haswell. As I remember, it can really fuck your day up.

+1, Haswell + Prime95 = bad day.

 

I've seen people ruin their chips by using Prime95, unsure why as to why they don't like eachother.

[CoronaBlue]

NEVER run Prime95 on Haswell. As I remember, it can really fuck your day up.

 

 

+1, Haswell + Prime95 = bad day.

 

I've seen people ruin their chips by using Prime95, unsure why as to why they don't like eachother.

 

Wow. Okay. Luckily mine is still staying at around 35 degrees as I type this. What utility should I use to ensure long term stability under a load?

 

Thanks for the quick replies, by the way. Folks on these forums are great.

[Flojer0]

I haven't read up on that cooler at all but looking at a picture of your cooler it appears to be more optimized for space than for cooling performance. Also remember that Prime95 is an unrealistically high load for most people. The most you will ever see on a bad day with anything else will be 10 degrees cooler than that typically. I wouldn't worry about it unless the computer is a work horse for you, I've seen laptops with worse cooling problems last years. But if it were me I'd want a better cooler if I had space for it.

[Superarragon]

NEVER run Prime95 on Haswell. As I remember, it can really fuck your day up.

 

I ran Prime95 on my 4770k a few times, and I have to agree with you... Even a 100-200mhz overclock will make my CPU go up to 90C on a Hyper 212 EVO.  

[Lord Pantaloons]

P95 makes Haswell draw more voltage than whats necessary and can damage your chip and give you terrible temps. I have a L9i and it's better than the stock cooler so these temps are not representative of the coolers actual performance, you should also keep in mind that CPU benchmarks will put your CPU under an unrealistic amount of stress that cannot be replicated by any game, the temperatures you see in a benchmark are unlikely to resemble what temperatures you will see while gaming.

[Flojer0]

I ran Prime95 on my 4770k a few times, and I have to agree with you... Even a 100-200mhz overclock will make my CPU go up to 90C on a Hyper 212 EVO.  

Man, that makes me feel extra glad I'm still on sandy bridge. On day's I feel very ambitious I have gone to 4.8GHz (a 1.4GHz overclock) and so long as my case and heat sink fans go full speed I don't break past the mid 80's.

 

 

P95 makes Haswell draw more voltage than whats necessary and can damage your chip and give you terrible temps. I have a L9i and it's better than the stock cooler so these temps are not representative of the coolers actual performance, you should also keep in mind that CPU benchmarks will put your CPU under an unrealistic amount of stress that cannot be replicated by any game, the temperatures you see in a benchmark are unlikely to resemble what temperatures you will see while gaming.

I have approached prime95 temps with some heavy computations I've ran. But pushing a computer like that is one of those things where if it's an issue you probably know it already. And it definitely doesn't happen in games.

[flibberdipper]

Wow. Okay. Luckily mine is still staying at around 35 degrees as I type this. What utility should I use to ensure long term stability under a load?

 

Thanks for the quick replies, by the way. Folks on these forums are great.

Use AIDA64 instead.

[nokturrduk84]

So haswell is bad chip? I ran my Ivy 3770k (4.2ghz OC) in prime with maximum 65 degrees. I'm glad I didn't buy Haswell.

[Faa]

Aslong as you don't hit 80° when gaming you don't have anything to worry about.  

[flibberdipper]

So haswell is bad chip? I ran my Ivy 3770k (4.2ghz OC) in prime with maximum 65 degrees. I'm glad I didn't buy Haswell.

It's not a bad chip by any means, but Prime95 makes it do weird things.

[nokturrduk84]

It's not a bad chip by any means, but Prime95 makes it do weird things.

Comparing to Ivy & Sandy it looks bad, if it can't handle stressing software, when Ivy & Sandy has no problem at all.

[deathjester]

Prime BLEND for one round on a haswell is ok. After that temps go bonkers.

 

AIDA 64 only adds 5-10 C past real world (rendering) temps.

 

Prime BLEND is still really good for a quick test on a memory OC or to throw in for a round in between Aida, Asus real bench, 3D mark vantage, Cinebench R15.

 

More tests are better. Run them all for like 10 minutes. Put computer to sleep and wake it up in between. If it passes them all? You saved yourself hours of boredom.

 

To test cache overclock (uncore) check just cache in Aida 64. Cache is what can crash hours in. 

 

It shouldn't take days and hours of testing to OC a chip. Start at 3500 cache (3900 is usually good to go, but some chips are picky). Get stability on max clock, which may require raising VCCIN. Raise cache. Test cache. Raise appropriate voltage if cache is failing.

 

Don't worry about cache if chip can't handle 1 to 1. Run all those stability tests for like 10 minutes, or 1 run (prime, 3d mark, cinebench single and multicore) or multiple runs on Asus real bench.

 

Should take under a hour. Game. No crashing? You win. If you aren't on dual rad water? Skip the hours of tests after you think it is stable. Running a chip at 80'sC plus doesn't help it, and proves nothing. Render some video instead or game. Lower temps, will find instability just as fast or faster.  

 

On older chips? Yeah. Air cooling? Test overnight etc. Haswell and AMD both run too damn hot for that now.

[harrynowl]

Wow. Okay. Luckily mine is still staying at around 35 degrees as I type this. What utility should I use to ensure long term stability under a load?

 

Thanks for the quick replies, by the way. Folks on these forums are great.

AIDA 64 or OCCT seem pretty mainstream choices for stress tests.