Guru3D Thermal Paste Roundup - Round 2 (2021)

#5974303 Posted on: 12/19/2021 03:03 AM

---

One extremely important factor with thermal compounds is the pump out effect. Laptops with crap cooling that cause high temperature deltas are extremely prone to that and I'm still having issues finding a thermal compound that doesn't escape from under the heatsink after a couple of months (somes are just days!).
For example, I have a Lenovo T490 that only spins the fan after 80ºC (nice design, right? no). The constant heat cicles cause the thermal compound to escape from the CPU die. So I start by having max temperatures of 85ºC and almost no fan spin and 1 week later the temperatures are above 90ºC and the fan spins everytime I do any activity like opening a simple browser tab. When I see the heatsink, the paste has migrated to the corners of the cpu and the die is almost without paste.


The die is supposed to be almost completely clean of paste with proper installation. When you remove the heatsink and there is a layer of paste on your CPU heat spreader thick enough where you can't read the text on the IHS, you've got bigger problems than thermal paste. Try taking a new razor blade and set the blade directly on the IHS or heatsink so its perpendicular, and hold it with a light source behind and check if you can see light between the blade and the surface. Even the most expensive heatsinks and waterblocks can suffer from bases that appear nice and flat but don't pass the razor test. Depending on how much a heatsink/waterblock is off in terms of flatness, i'd either lap the surface or use something actually designed to work as a gap filler like a carbonaut thermal pad
Intel CPU's from my experience have gotten much better in terms of flatness than they used to be. My current i7-10700k was very flat and my last chip, an i5-4670k was a little concave. An old Core 2 Quad ive got in a box here was very concave. Both the heatsinks and waterblocks i've owned over the years tend to vary widely in terms of flatness, so much so that i've had to lap every one of them in my personal system for about the past 15 years. On a few occasions, like with my 4670k, i had to lap both the CPU and waterblock (and delid + shave IHS so it sat lower) to get good contact. Usually just the heatsink is enough.

#5974304 Posted on: 12/19/2021 03:18 AM

---

You might want to read this about the 12xxx series
https://www.igorslab.de/en/bad-cooling-at-alder-lake-problems-at-socket-lga-1700-on-the-lane-among-all-remedies/

Summary:
It appears many motherboards/sockets bend causing the core lids to bend!
wtf?

#5989124 Posted on: 02/02/2022 05:45 PM

---

Posting here to say i just replaced my MX-4 for MX-5 and it's just extremely disappointing, this thermal paste is impossible to spread correctly it's literraly trying to spread a chewing-gum on the CPU.
From Arctic videos the paste seem liquid enough but that's not at all what you're getting from stores, it's dried out chewing-gum, i had to start over 4 times and even now i'm not getting as good results as with MX-4.

So disappointed. Ordering another thermal paste right now.

#5989128 Posted on: 02/02/2022 05:49 PM

---

Posting here to say i just replaced my MX-4 for MX-5 and it's just extremely disappointing, this thermal paste is impossible to spread correctly it's literraly trying to spread a chewing-gum on the CPU.
From Arctic videos the paste seem liquid enough but that's not at all what you're getting from stores, it's dried out chewing-gum, i had to start over 4 times and even now i'm not getting as good results as with MX-4.

So disappointed. Ordering another thermal paste right now.
There may be a bad batch, I've not heard that said about MX-5 before.
Sadly I havent tried it though.
I would get in touch with them and state your woes.

It might even be a fake!

#5989133 Posted on: 02/02/2022 06:09 PM

---

Posting here to say i just replaced my MX-4 for MX-5 and it's just extremely disappointing, this thermal paste is impossible to spread correctly it's literraly trying to spread a chewing-gum on the CPU.
From Arctic videos the paste seem liquid enough but that's not at all what you're getting from stores, it's dried out chewing-gum, i had to start over 4 times and even now i'm not getting as good results as with MX-4.

So disappointed. Ordering another thermal paste right now.

MX-5 is supposed to be less viscous than MX-4 (thinner/runnier) so as @Mufflore says, definitely must be a bad batch or counterfeit paste you have