15" Mid-2014 MBP thermal throttling

[Peet_B]

Hi guys,

I've been experiencing some major thermal throttling taking place on my mid-2014 15" MBP. I replaced the thermal paste for some Thermal Grizzly Conductonaut liquid metal about 2 years ago. After I did the thermal paste replacement my thermals were great, with a maximum of 88C with 100% CPU usage and no thermal throttling.

However since a couple of months using my MBP with just simple tasks and not more than 60%-70% CPU usage, the temps rise up to 99C with the fans at full blast. When I do a stress test the indicator shows that only 79% of the CPU performance can be used due to thermal throttling, and my idle temps rarely go under 50C... All of this happened gradually upgrading from High Sierra to Mojave to Catalina. Is there any chance my liquid metal has lost its efficiency? I read somewhere that it could last for up to 5 years... I regularly blow out the fans and heatsinks, so there is absolutely no dust present in the machine. Do some of you guys have some tips or similar experiences?

 

[maflynn]

It might be do the higher demands of the new operating system, personally, I refrain from upgrading my old laptops to the latest OS version. If the CPU is showing to be under load for much of the time, then the heating isn't due to thermal paste or dirty fans (though cleaning them will help) and more because the CPU is being pushed harder with the newer operating systems.

 

[Peet_B]

It might be do the higher demands of the new operating system, personally, I refrain from upgrading my old laptops to the latest OS version. If the CPU is showing to be under load for much of the time, then the heating isn't due to thermal paste or dirty fans (though cleaning them will help) and more because the CPU is being pushed harder with the newer operating systems.

But that leaves me wondering. My girlfriend has a 13" mid 2019 base model MBP, and on paper they are identical CPU performance wise. My 2014 MBP has way better cooling with not only 1 extra fan, but a beefier heatsink in general, and still heats up a lot more than her 2019 MBP... For the heavier work I've got a 12-core cheesegrater Mac Pro, but it annoys me a lot every time I do simple tasks on my MBP and it starts blowing like it wants to go on some sort of SpaceX mission... Don't think removing the liquid metal and applying regular thermal paste will help?

 

[xnsys]

From past experience - thermal grizzly needs to be replaced every 8-12 months - and does deteriate and is better suited at an overclocked PC.

I've changed the TP in my 15" with Arctic MX-4 and that's supposed to have 8-years life, although doesn't have as as high level of thermal transfer as the grizzly, it will last longer and makes enough difference.

Thermal throttling is still there, but not as intrusive.

Personally, after taking the machine apart and seeing the size of the heatsink I'm not at all surprised that there is heat issues - it's tiny and the amount of air that would need to flow over the fins to expel all the heat generated by the CPU and GPU would be a lot.

 

[Peet_B]

From past experience - thermal grizzly needs to be replaced every 8-12 months - and does deteriate and is better suited at an overclocked PC.

I've changed the TP in my 15" with Arctic MX-4 and that's supposed to have 8-years life, although doesn't have as as high level of thermal transfer as the grizzly, it will last longer and makes enough difference.

Thermal throttling is still there, but not as intrusive.

Personally, after taking the machine apart and seeing the size of the heatsink I'm not at all surprised that there is heat issues - it's tiny and the amount of air that would need to flow over the fins to expel all the heat generated by the CPU and GPU would be a lot.

I understand that normal thermal paste loses its top performance after about 8-12 months, but does that count for liquid metal as well? That stuff doesn’t dry out/evaporate... anyway, I’m going to clean it today seeing if I can improve anything

 

[xnsys]

Liquid metal is good for a permanent bond - it eats into the surface of the heatsink from previous experience, and potentially the CPU - you would need to use a conformal coating on the CPU to ensure that any movement of the liquid metal to the surface of the CPU wouldn't cause any shorts.

 

[Peet_B]

Liquid metal is good for a permanent bond - it eats into the surface of the heatsink from previous experience, and potentially the CPU - you would need to use a conformal coating on the CPU to ensure that any movement of the liquid metal to the surface of the CPU wouldn't cause any shorts.

I applied this liquid metal about 2-3 years ago and it has never caused me any trouble. I’m curious if it is even a good option to ditch the liquid metal and go back to “regular” thermal paste like Kryonaut.

 

[Peet_B]

This is a screenshot of a minute ago. As you can see the CPU and GPU are barely doing anything but it's still at 88C with the fans being audible...

 

[xnsys]

First things first - I would lift the case off and look at the state of the fans - clean them out if necessary - failing that I would then investigate further.

Can you feel any air coming out from the fans at the back?

 

[Peet_B]

First things first - I would lift the case off and look at the state of the fans - clean them out if necessary - failing that I would then investigate further.

Can you feel any air coming out from the fans at the back?

I cleaned them out 2 weeks ago, and there is enough air coming out of the back I use a compressor with a filter to blow the machine out regularly, so there is absolutely no dust causing issues.

 

[xnsys]

Then further examination is needed, could be that the thermal paste being liquid metal has run off the CPU and causing issues - difficult to tell without investigation.

I'm not a fan of the stuff as seen what it can do to CPUs in servers, where it's welded the heatsink to the CPU - and also have seen it dripping from CPUs that are mounted vertically...

Wouldn't ever use it myself as the difference it makes is negligible when compared to a decent thermal paste that's been applied properly - the only advantage of the liquid metal is that if you apply if badly you still get a good level of thermal contact.

 

[Peet_B]

I removed my “liquid” metal and replaced it with some kryonaut Cinebench R20 scores went up by almost 200 points! The “liquid” metal had solidified completely and fused itself to the heatsink... I sanded it all down with some fine sand paper, applied the Kryonaut and voila!

 

[xnsys]

That's exactly what the thermal paste does, and exactly why I wouldn't ever use it in any machine.

Good work and glad it's sorted it for you.

 

[Peet_B]

Yeah, when I applied it all that time ago, it was something “new” and everyone loved it. But since there was no real “long term test”, I assumed it was all fine, especially since they claimed it would last for up to 5 years...

 

[xnsys]

What state was the processor in - I've seen servers type E5-2690 with the metal casing completely melted by it.

 

[Peet_B]

Luckily it was fine, the liquid metal was sort of fused to it, but with a little scrubbing with some cotton sticks and alcohol I got it all off the CPU dye, though the GPU dye was a bit more stubborn and I couldn’t get it perfect. Since it was ok and didn’t want to sand it down as well I left it as it was. No more liquid metal for me though.

 

[xnsys]

I think that's a lesson to everybody who wants to give it a try - stay away from it unless you're happy to replace the CPU and associated accessories when you replace the thermal paste.

You're fortunate that the CPU wasn't damaged.

 

[Icehart]

I had a similar issue with A1398 2015 model. I applied thermal paste some 7 months ago and was surprised to see it completely dried up in my recent periodic maintenance of the fans.

Could be the thermal paste doing its job really well. I can't complain much here since these thermal pastes are relatively cheap and easy to replace.

 

[xnsys]

I had a similar issue with A1398 2015 model. I applied thermal paste some 7 months ago and was surprised to see it completely dried up in my recent periodic maintenance of the fans.

Could be the thermal paste doing its job really well. I can't complain much here since these thermal pastes are relatively cheap and easy to replace.

Depends on the machine - pain in the ass getting the cables out the way with the newer MacBook Pro's - and only so many times they can be disconnected and reconnected before they break.

 

[Icehart]

Depends on the machine - pain in the ass getting the cables out the way with the newer MacBook Pro's - and only so many times they can be disconnected and reconnected before they break.

A1398 was probably the last Macbook Pro from Apple that is durable.