Processors

[amhungry]

Hi,

When I attach a cooler, the thermal paste is not spreading evenly over the CPU. It gathers around the edge, with a band down the middle with very little paste. This is accompanied by poor benchmarks. I have tried two coolers which both showed the same behaviour.

I've attached photos of the paste pattern and the benchmarks.

Computer specs for reference:

Case: CoolerMaster NR200P
Cooler: Noctua NH-L12S
Motherboard: MSI B650I Edge Wi-Fi
Graphics: ASUS Pro Art RTX 4080
RAM: G.Skill 32GB 6000 Hz

 CPU benchmarks. 2nd percentile with 0% background CPU usage

Thanks,

amhungry

[elstaci]

Remove the ryzen processor and clean the surface with 90+ pure isopropyl alcohol to remove all left over thermal paste.

Then get a thin metal straight edge and very carefully lay it across the surface of the processor. Now in a dark or dimly lit room use a flashlight to illuminate one side the of the metal straight edge.

Look at the surface of the processor on the dark side. You shouldn't be able to see any light filtering through the bottom of the metal straight edge or a extremely thin line of light that is even all across the processor.

If you see a large gap of light in the middle of the processor that means the surface of your processor is not even or distorted.

In that case I would open a AMD Warranty ticket to have it replaced with photos showing the gap in the processor's surface.

[amhungry]

This is brilliant advice thanks! I'll give it a go tonight and get back to you.

[amhungry]

So I tried the straight edge test and there was no obvious bow on the processor. But good to cross one possible problem off the list. Thanks again for the suggestion, I wouldn't have thought of it myself

[ScornfulWizard]

---

@elstaci wrote:

If you see a large gap of light in the middle of the processor that means the surface of your processor is not even or distorted.

---

Wait, shouldn't it be the other way around? It seems to me as if it is the middle part that is making close contact with the cooler's plate and pushing the paste to the uneven downsloped sides (illustrated). 

[elstaci]

Good point and illustration.

Either way OP needs to see if the CPU surface is somehow distorted, which is hard to believe, but his photos are hard to disprove also.

[amhungry]

Thanks for the illustration. This is what I was thinking as well. I have no idea how something like this could happen, so it's hard to work out what the fix might be

[ScornfulWizard]

Well, grinding your CPU's surface down to perfection will definitely be a little bit of an overkill brute-force solution, but as a viable alternative you can try using a moderately thick thermal pad (for CPU specifically, not just general purpose) that might absorb the unevenness of the surface with enough pressure. You will lose from around 3 to 10 degrees in temperature, comparatively, but if it's better than before, then it's the way to go, I'd say. Not the best option, but an option nonetheless ¯\_(ツ)_/¯

[amhungry]

That trade off might be worth it. Thanks for the idea!

[ScornfulWizard]

Unironically using UserBenchmark's data to meter the performance...

[amhungry]

Thanks for your reply. I always like better data. I like that the UserBenchmark automatically compares with like parts. Which benchmarking tool would you recommend?

[ScornfulWizard]

I used to blindly gaze upon various benchmarks and data too, but then I realised that what matters to me the most is the current performance I'm experiencing, the pure empirical data - in other words, my personal impressions.

However, this is slightly off-topic, to be honest, so... to go back on track - always use several sources of data for comparison: there are enough other benchmarking services apart from UB - use them, check the published lists and compare the numbers they provide (PassMark, Cinebench, 3DMark, Geekbench and so on). My joke about UB was done simply due to how frequently they'd been caught skewing the testing results (specifically against AMD's CPUs). In conclusion, if your CPU is still within the designated performance window, it's not such a big problem.

[ThreeDee]

maybe ... and only maybe .. an AM5 Secure Frame Mounting Bracket from Thermalright would help ..maybe

I use them on my 2 AM5 builds .. 

[amhungry]

These look great! Definitely worth a try. I remember seeing something similar for Intel CPUs that bend when they are secured. It'll take a while, but I'll report back when I've given it a go

[goodplay]

May also be the cooler base being 'slightly Convex' (from 1 reviewer), might want to check that also?

[elstaci]

That was my first thought also but the OP wrote that he used 2 different CPU Coolers with the same results thus I figure the issue was with the CPU's surface and not the CPU Cooler's surface.

[amhungry · Accepted solution]

UPDATE:

Thanks all for your help.

I noticed that the thermal paste hadn't spread all the way to the corners of the chip, so I made sure there was coverage there. Now the benchmarks consistently place the chip in the 10-20th percentile when compared against other 7600X. Not great, but it's at least comparing decently with some other 7600X chips.

This confirms to me that the poor results are due to thermals. I've ordered the thermalright bracket that ThreeDee suggested to see if it helps with the seating.

Now I feel confident that the chip is within the performance window, so from here on it's just tweaking to get the best out of it.

Thanks again for all of your suggestions. I'll update with results in case it helps anyone else.

[elstaci]

Good to know. Why don't you mark your last reply as "Solution" so that other would know what fixed your issue.

[amhungry]

FINAL UPDATE:

I've installed the thermalright bracket suggested by ThreeDee. It has brought the results up a few percentage points. Now the benchmarks bottom out at 20th percentile and sometimes go as high as 48th percentile.

As far as I'm concerned this brings it into the performance window that I expected when I bought the 7600X.

In summary, anyone else experiencing this problem should make sure that the thermal paste is spreading ALL the way to the corners. If you need help getting even contact between processor and cooler, the Thermalright bracket did improve performance by a little bit.

Thanks everyone for your help!