Core i7: Temp Diff under load?

[XPiRX]

Hello,

I recently built an i7 860 build with a Noctua DH-U12P heatsink. I used the pea method when applying the Noctua thermal paste. My idle/load temps are right where I want them to be. High 20s/Low 30's during idle and high 40s on load.

My only concern is that my Core 0 is 5-7C hotter than the rest. During load and idle this core likes to stay hotter than the other three. The difference is less when under load but its still about 3-4C hotter than the the other cores which are within 1-2C of each other.

Im going to try to reapply thermal paste using the the line method as shown on the AS5 website instead of the pea. Also try and lay my case on its side so the heatsink is straight up and down. I heard that heavy heatsinks can drag down ever so slightly and make temps a bit hotter in certain cores.

Any ideas besides reapplying thermal paste? It's not the biggest deal but I would prefer the temperatures to be relatively close within 1-2C of each other. I figured core0 would be the hottest during idle because its utilized first/the most but not during load.

Here are temps under load for about 15 minutes with Prime95.

 

[aigomorla]

These are on stock settings correct?

core 0 is turbo'd +2 under load im guessing.

You need to see your turbo states.

Otherwise it could be you have a bad mount.. or improper tim layout.

Its not really that bad... if it bothers you, remount.

 

[Kenmitch]

Any ideas besides reapplying thermal paste? It's not the biggest deal but I would prefer the temperatures to be relatively close within 1-2C of each other. I figured core0 would be the hottest during idle because its utilized first/the most but not during load.

Not sure if doing it again would help or not. Most of the time it's due to the heatpspreader. I wouldn't worry about it.

More importantly what was the point of buying the l7 860 if your not gonna run it with hyper-threading enabled.

 

[Diogenes2]

Why would you think hyperthreading would be the only reason to use the 860 ?
What would you suggest as an alternative ?

 

[Kenmitch]

Why would you think hyperthreading would be the only reason to use the 860 ?
What would you suggest as an alternative ?

The i5 750 would be for those going S1156 and don't want hyper-threading. Best bang form buck....Other than the ocassional microcenter deal.

 

[TankGuys]

I'd remove the heat sink, clean all your TIM off, and start fresh. The only thing under your control that would cause this would be a poor application of TIM - either not enough, or too much. So just to be safe, if you're worried about it, do it again.

I am skeptical that mounting direction would have much of an effect. Assuming you have a proper mounting kit and it's installed properly, there should be more than enough mounting pressure from each direction to make that minor change moot.

If the re-application of TIM still doesn't solve it, then it's most likely a poorly seated heat spreader on the CPU package - which isn't something you can fix ... or, at least, not something you want to try!

Regardless, it's not something to lose sleep over. Unless you start heavily overclocking this thing and are pushing the thermal envelope, it's hurting nothing by having a core or two run a few degrees warmer

 

[Supersonic64]

A difference in temperature between cores is absolutely NORMAL. There is always one core that tends to run a bit warmer than the rest and it is nothing to worry about. You could try reseating your cooler a million times and that one core will always be warmer than the rest. Just let it be.

As far as hyperthreading is concerned, it does substantially increase the heat output of the chip especially when under load. Is hyperthreading really needed with 4 physical cores? No, probably not unless you run some very well multithreaded apps which are still far and few in between.

 

[XPiRX]

I turned HT off because I get better performance with it disabled. I get on average a 8GFlop gain compared to HT being enabled. Also, with HT enabled some of my games have issues just installing to the computer, all problems gone when its disable. HT enabled also makes my CPU run a lot hotter.

I also disabled Turbo mode in my bios, but for some reason its still being reported as on in Everest. My multiplier never goes to 22x though, so I don't think its on, but reporting wrong.

I remounted, temps are the same as before. So i assume its just the CPU itself.

And the reason I got the 860 was because it was only 30$ more than the i5, rebates are awesome. So why not spend 30$ more and get the better chip? I can overclock this to 4.0ghz stable on air, under 1.4v too. 75C Load(48c idle). My room got way to hot though since it summer, so put it back to stock. Cant wait for winter

 

[richierich1212]

Isn't the 860 essentially a 750, but with HT?

 

[XPiRX]

Isn't the 860 essentially a 750, but with HT?

Idk, is it? lol Looking at charts, the 860 is like 5% more performance. So basically, yeah. I had a friend help me make a setup, I didn't really do much research. I haven't been into hardware in a while. Money wasn't an issue, so I just purchased and built SSD FTW Though, Cant beleive how much faster it is.

But the HT lowers my performance and causes problems. So that is staying *OFF*.