CPU Cores 0 and 1 are much hotter than the others

[Kukiezi]

Hi!

I have i7-4790k. I wanted to overclock it after a few years and found out that my temps are very weird under 100% load. Checked for both prime95 and intel burner. My Core 0 gets almost instantly to 100 degrees and Core 1 to around 90 while the others stay at good temp. I did replace thermal paste and checked my voltage settings aswell as if cooler is running correctly (be quiet! Shadow Rock Slim). I know my cooler is not the best, but I am sure it shouldn't cause 30 degree temp differences between cores. I am quite out of ideas and don't know what to do anymore. I have found a few threads with almost exactly the same issue across the internet, but no real answer was found.



I also checked temps in programs like hwinfo and core temp. The same everywhere. Also under lower load Core 0 doesn't go to 100 degrees and on idle it looks very good as well.



I think it is not a processor's fault, but I can't be sure anymore. If anyone had issue like that and managed to fix it? Or have any good ideas I would appreciate it a lot.

Thanks!

 

[wagex]

seems like intel did a bad job of applying the thermal paste between the processor and the integrated heatsync. Generally an issue like this is solved by delidding and applying a better thermal compound between the cpu and the IHS.

 

[EarthDog]

Yeah, wow... a 30C difference between cores is a ton... If you are sure the thermal paste spread was good (covered the whole IHS / not too much applied) and the heatsink mount is good (did you take the plastic off the bottom??) then I would say a delid is the answer...

 

[WhitehawkEQ]

Yeah, wow... a 30C difference between cores is a ton... If you are sure the thermal paste spread was good (covered the whole IHS / not too much applied) and the heatsink mount is good (did you take the plastic off the bottom??) then I would say a delid is the answer...

This looks like 1 other user who forgot to take the plastic label/sticker off the bottom of the HS, check your HS for this label/sticker.

https://www.overclockers.com/forums/showthread.php/792143-High-temperatures-FX-6300

 

[Kukiezi]

This looks like 1 other user who forgot to take the plastic label/sticker off the bottom of the HS, check your HS for this label/sticker.

https://www.overclockers.com/forums/showthread.php/792143-High-temperatures-FX-6300

I will check tommorow for the sticker. I just found this topic
https://www.overclockers.com/forums...-Core-0-runs-much-hotter-than-the-other-cores

And seems like the same issue, but hard to tell if the answer was found... overall user switched motherboard and seemed to fix this. But yea motherboard switch is not so simple so I am looking for more possible reasons than that.

Will also try to put my CPU in friend PC to check if temps are better to make sure CPU is not at fault.

 

[Kukiezi]

So I made a test today. I switched my CPU for my friends CPU. And temps were great and stable. So that points into faultry processor which is good in a way because now I made sure its not something else. So now I thought dedling is a good idea. But I called some computer services in my city and most of them do not offer this and if someone offers, I would explain them the problem and they would say there is no way dedling can fix 30-40c difference issue and those temps are impossible. So they pointed into faulty temp sensors. But I have 4 cores and for some reason two of those would be faulty. I could turn of sensors and just belive its faulty sensor but I am not sure if its a greatest idea...

 

[Zerileous]

Just pop it yourself https://www.aliexpress.com/item/32889691900.html. Watch some youtube videos first, but it shouldn't be super challenging. Otherwise post a request in the classifieds, I'm sure someone here will be glad to do it for a reasonable fee. If not these guys will do it https://siliconlottery.com/collections/sl/products/delid?variant=19733402288214

 

[mackerel]

If you let the CPU go idle, what temps does it report then? That might give a clue if it is sensors or not.

Edit: I see in the image on 1st post the minimum temps are around the same and look believable. Personally I'd lean towards trying a delid+repaste.

 

[Kukiezi]

So deliding has been finally made and I can say temps are now way closer and more stable. The biggest difference I see is around 10C in high stress test situation. Also they didn't use metail in deliding which is kind of bad but works for now. I think the next step would be to get new cooler for my CPU since temps are still not ideal, but at least no jumps to 100C on two cores.

To anyone with issue as mine I suggest deliding. One part of my cpu core had almost no paste on it which caused those temps

 

[Kukiezi]

A little update for You guys. So the company that made delidding for me did a ****ty job. The temps after 1 days went high on all cores. I was worries so I decided to take care of it. I ordered everything I need for delidding with liquid metal. After opening the CPU this is what I found.



So I delidded the CPU again. That was stressful but worth it after all. This is how it looked like after delidding:



Now I can handle 5.0 Mhz with this beast. Temps around 90C with 100% load. On 4.6 Mhz on 100% load its around 50C which is great. I am really surprised with the results and I actually encourage everyone with problems like me to delid the processor. Oh also I bought new cooler "BeQuiet Dark Rock Pro 4" which didn't help until I delid the CPU. But after delidding it's actually helping a lot.

Thanks to everyone who replied to me during this CPU journey.

 

[Zerileous]

wow that was a lot of paste. Looks like a good job on the LM

 

[Mandrake4565]

That 1st picture, wow that's a lot of paste. Glad you had good results with the LM. One of these days I need to do the same to my 4770k I also have one that is in need of a delid. Next thing you need to do is work on your handwriting.

 

[zexer2020]

Hey just wanted to update the topic with my results because I had the exact temp problems and this topic encouraged me to delid my Intel Xeon E3 1246 V3. IT WORKED!! I have never been hapier in my life! windows booted like always and now core temps are much closer to each other and in the normal range! Uploaded the pictures (cooler is the intel stock one for now so temps will be even lower after i get a better one).
Delidding is really stressful if it's the first time you are doing it but if you research thoroughly and watch enough youtube videos and be patient in the process, it won't be difficult to do.