Effect of reapplied thermal paste on new Macbook?

[joptimus]

Hi guys,

I'm following the discussions about throttling in the new MBP 2018.

Aside from using Volta to limit TDP/disabling Turbo, one might also think about reapplying the thermal paste (possibly substituting with a higher quality one - not metal based of course).

I understand this may have a good benefit on older machines where the original paste has dried. How about a brand new one?

Please don't discuss about warranty. I'm purely interested in the technical side of this.
Does it provide (significantly) lower temps or not on a new laptop? I couldn't find any reviews/posts on that.

Thanks!

 

[Lennyvalentin]

Please don't discuss about warranty. I'm purely interested in the technical side of this.
Does it provide (significantly) lower temps or not on a new laptop? I couldn't find any reviews/posts on that.

It's hard to say for sure if there are potential benefits without having actually DONE it. 🙂 Theoretically, yes there might be (usually no more than a few degrees C though), but that would also depend on stuff like Apple actually using bad quality paste for example - which seems a dumb thing to skimp on considering the savings vs. a quality paste would be incredibly marginal per laptop, while the negative effects on your $2-3k premium laptop would probably represent a larger value than the cost of a dab of quality thermal paste. So classic case of shooting yourself in the foot really.

IIRC, people have re-pasted their Macbooks and noticed improvements, but I wouldn't expect a miracle, honestly. Using high-power desktop processors, the difference between a top of the line paste and lipstick (!) is like, 5-7C or something like that. So if Apple is using a decent paste, and putting it on a chip with much lower thermal output in the first place, we might be talking maybe 1-3C or so. Is that really worth the effort?

The most important thing is not have an air gap between the hotplate (or bare silicon die in this case) and the heatsink, because air is the worst heat conductor of them all short of a vacuum. Other materials will often perform at least decently as long as the layer is kept thin. The thinner the better - again without introducing any air.

 

[maflynn]

Based on prior experience and also from what I've seen on youtube, you may see 5c improvement, maybe even a bit more, but the savings isn't going to huge.

 

[Schranke]

Did it on a new 2017 machine which is 3 moths old, and you see an improvement on around the 5c as @maflynn said. I am able to maintain turbo boost of 3.5Ghz but I do still hit high temperatures flooding around 95c when doing synthetic benchmarks.
I am in the general opinion that all Macs will benefit from getting re-pasted as apple generally applies to much compared to what one with experience would do.
It would be nice to know what the difference is if the stock paste was applied like one would do when repasting, here I think the temperature difference will be much less

 

[maflynn]

all Macs will benefit from getting re-pasted as apple generally applies to much compared to what one with experience would do.

That and you have the option to use some significantly higher end compound - still its not a magic bullet to solve the throttling issue

 

[Mr Screech]

Would it really matter with a CPU that needs so many watts?
The chip would heat up slightly slower with better cooling paste, because the transfer of heat from cpu to the cooling system would be faster.

You need airflow to remove the heat.

 

[joptimus]

Thx for the replies.
I agree it won’t fix anything on its own, but with TDP limit and undervolting (seems not to work on newer Macs?) it might contribute well.

 

[Schranke]

Thx for the replies.
I agree it won’t fix anything on its own, but with TDP limit and undervolting (seems not to work on newer Macs?) it might contribute well.

not on its own, but @Aea have made some good results on his i9 bu limiting power
https://forums.macrumors.com/threads/2018-mbp-i9-testing-w-volta-fan-control.2128797/

still its not a magic bullet to solve the throttling issue

unfortunately not, and for the 2018 machines I do not think the effect will be enough, it did on my 2017, but I do not have the 2 extra cores generating heat