Tiny scratch dots on IHS and cooler

[magicxcian]

I recently built a new computer and today I decided to reapply thermal paste as CPU temps seemed a bit too hot. When I cleaned the CPU and the heatsink I noticed there were some bumps I couldn't clean off. On further inspection it looks like there are little matching scratch marks:

CPU IHS: https://i.imgur.com/aOV2vPY.jpg
Cooler: https://i.imgur.com/mkvbEmH.jpg

CPU is i7-8700k, heatsink is Noctua DH-15s. I had repasted it twice before, once with Noctua NT-H1 and once with Thermal Grizzly Kryonaut. I used the pea method. The coverage seemed fine and there weren't any bits in the thermal compound, so I am at a loss as to how those scratches got there. Is it something to be concerned about?

P.S. Do the following temps seem normal? I'm currently running Prime95 (no AVX) with the i7-8700k at 4.9 GHz, Vcore=1.256 V. Temps are steady at 88 C with the CPU package drawing 141 W. The CPU is not delidded (yet).

 

[jojesa]

Most thermal compounds (aluminum and zink oxide) are abrasive and could scratch both the IHS and heatsink.
Also the TIM could baked creating bumps or taking chucks of the IHS.

When you are replacing a heasink try doing it when it is still hot to avoid that issue.

I have encountered bigger scratches than that, and I don't think it makes a difference.

 

[shmoochie]

Yeah, a rough detach could do that for sure. You could just sand them off with some high grit sandpaper if you are worried they are affecting thermals.

 

[geofelt]

You are good.
Those scratches are located away from the heat producing parts of the cpu.

The purpose of paste is to fill in small pits in the mating surfaces.
My best guess is that there was some debris on the chip or the cooler and that when the cooler was installed, and heated the pits formed.
You could lap and polish the surfaces if you were obsessive about it.
I would not bother.
Your temperatures seem normal.
I would expect to see 10-15c. over ambient at idle in a good case.
4.9 with a vcore of 1.256 is excellent.

FWIW
as of 3/22/2018
What % of I7-8700k chips can oc
at a aggressive vcore near 1.4 or so and delidded
4.9 99%
5.0 88%
5.1 54%
5.2 22%