Delid or second fan.

[Jason Rage]

Hello everyone

I have hit my temp wall overclocking my 8600k. I can run 5Ghz stable @1.34v but only with an AVX offset of 1.

Prime95 AVX & Intel Burn Test very high both push my hottest core to 89C. If I remove the 1 AVX outset I fail the stress tests. Any more volts I push 90C. So really a no go!

I have 2 options, install a 120mm fan over my high profile ram onto my Noctua NH-D15S or delid to apply some liquid metal.

So my question will a further 120mm Noctua fan make any real difference or is delidding my only option left if I want to be able to run stable 5Ghz with no AVX offset?

Thank you

 

[Jason Rage]

I have a NZXT Full Phantom that I custom modded removing the old HDD tray bays for better airflow and open space. On top of this case are 2 200mm horizontal mounted Phanteks. One sits above and just in front of the CPU cooler pushing 110.1CFM/1.04mm static pressure threw no dust filter only a metal mesh directly into the Noctua cpu block. The rear top mounted 200mm is exhaust above and behind the cpu block. Directly behind the cpu block is a 140mm Fractal Dynamic X2 exhausting as well. At the bottom front I have a 120mm Fractal X2 pushing air directly into the GPU behind mesh no dust filter as well. I control these using a manual control set to max rpm when overclocking.

Working with what I have I have tried my best to create good airflow in my case. Its this reason alone I have not upgraded my case with the current trend of closed case fronts etc.. Coolmaster Mesh was an option but personally dislike the look of it.

Am I doing something wrong here or are we looking at the limitations of the cpu itself? Might delidding be the way forward for me?

P.s I can place my hole hand in front of my cpu cooler, I have done this many times to check the airflow and temperature. Cold air goes into the front of the cpu block and all hot is exhausted at the rear.

 

[Jason Rage]

De-lid.
An extra fan will give maybe a couple of degrees less. A delid done properly will pull worst case 10 degrees, best case 20 off.

So it looks like delidding! Must admit a tad nervous doing it myself. Do you know of any reputable company that does it at a reasonable price?

Thank you Doyll & Steveocee for your help!

 

[Jason Rage]

Have you read the info in link I gave you? In it I tried to explain the principles of airflow hand how to apply them to a normal tower case.

Our hands in front of cooler don't give you much if any idea how much airflow ther is or what temp it is .. and if case is open the air temp will be much differnt then if case is closed.

Yes I did read it. Found it very interesting. Bookmarked for future reference. All I can add is that I have had this case for many years and tried a verity of different fan mountings. From 200mm side panel fan to the 2 120mm fans at bottom( Useless really as exhaust straight to other side of case) to no top exhaust etc.. I was worried about the top rear exhaust push/pulling heat back in and ran benchmarks using Core Temp, Hwinfo64 with it disabled to see. No real difference.

Remember also that I have a fan controller allowing me to adjust my fan speeds to tweak pressures. Also it takes 2 seconds to the remove the front and top panel, another 3 seconds to remove the side panels. Running prime with AVX instructions but with all of the panels removed, effectively very close to an open air test bench, creates a difference in temperatures of 1-2 degrees max. Really, I have tried every possible mounting, configuration, open aired testing, etc.. and can pretty much say imho that airflow is not the issue for me. My tower is huge with plenty of space and running benches with all panels of with no real change in temps is a testament that its all working as intended. Non overclocked idles temps are in the 20C, overclocked at 5Ghz in the 30C.

I think Steveocee has hit the nail on the head and its coming down to the poor TIM. Other activities like gaming, Frostpunk for instance, running on ultra using nvidia 4k synthetic (DSR) resolution never brings my hottest core above 61C clocked at 5Ghz. Heat is only a problem when benchmarking the toughest stress tests out there. A lot of people don't even bother with Prime95 AVX anymore because of the unrealistic workload and heat production.

If as steveocee says, 10 degrees of worse case scenario after delidding, will mean I am running prime95 AVX at 5Ghz in the 70C range! At best 60's!

That will do very nicely indeed!

 

[Jason Rage]

I can see what your getting at Doyll. I think you approach your builds very scientifically and coach & tinker everything down to the tinniest detail.

I'll grab a remote sensor and try to see my temps going into the cpu cooler, what could it hurt? Something like the Exo Terra Digital Thermometer, it has a suction cup on for easy mounting for £9 on Amazon. If it does not help now does not mean it might not be helpful in the future especially when I finally upgrade my case to one I like, save hours of tinkering.

Even so, if there is an airflow issue naff all I can do about it other than replacing the case. That probably means upward of £100. However, delidding will cost me less than £40 with more than likely similar if not better results.

But ultimately, delidding is the way to go for me. I watch Gamersnexus, jayz2cents etc & know the difference delidding has but there is no video showing results of say adding a second cpu fan, hence my original question of fan vs delidding.

Thank you again Doyll and Steveocee, I think my question has very much been answered now!

 

[Jason Rage]

what temp do you get doing normal activities? why not reduce frequency and voltage

With adaptive overclock 20C range Idle. Max is in the 50-60C range gaming. Just to keep things easy I have set an AVX offset of 2 for a 4.8Ghz when benchmarking. So now I have a fully stable adaptive 1.34v (1.165v with adaptive offset of 0.175 for 1.34v) 5Ghz overclock for non AVX & 4.8Ghz for AVX.

Temps hit 91C on hottest core if I add more voltage to lower AVX offset on Prime AVX or IntelBurnTest Very High.

Good new is that if I do delid pretty much guaranteed to run 5Ghz without any AVX offset.

 

[Jason Rage]

Those temps tend to indicate heat transfer from chip is pretty good. How long does it take for temps to reach 90c once you push CPU to high load?

Not long tbh. Within a few Prime cycles. Maybe as little as a few minutes its settles.

Actually dropped this overclock now as noticed that a lot of programs & games use some form of AVX as I was pretty much running at 4.8Ghz. Only non AVX Prime seemed to really utilise the 5Ghz. Currently testing at 4.8Ghz 1.295v. Well bellow 90C now and amazed at how much more voltage, lets not forget the heat, you need just for the extra 200 mhz.

Ill let you know what my final voltage & heat is as still testing and dropping.

 

[Jason Rage]

4.8Ghz 1.29v. After running a few hours max temp recorded 87C.

When I first bought the cooler was getting similar heat results at higher speeds. Think I might strip the cooler down for a good clean. I have an air pressure tool but reckon its time for a wash to get all of that secreted dust out.