Question Does anyone routinely check the heat sink grease on the processor?

[Alan Alan]

I didn't actually check mine intentionally on a 5 year old system but the grease has dried up and is dark in color. I just wiped it off and added new grease before I put the aio back on. I've seen real old thermal compound turn to powder but this is 30 -50 year old audio amplifiers. I wouldn't think new types of compound would do this. This worries me, I hope it's not planned obsolescence. Just curious if others have seen this.

 

[Lutfij]

Happy New Year!

Thermal pastes can pump out over time. To add some more context to your predicament, can you state the full specs to your build and what your ambient room temps are as is the case with idle and load temps prior to the thermal paste reapplication? What thermal paste did you use to replace the one that had dried up? Make and model of the cooler used?

 

[Alan Alan]

Happy New Year!

Thermal pastes can pump out over time. To add some more context to your predicament, can you state the full specs to your build and what your ambient room temps are as is the case with idle and load temps prior to the thermal paste reapplication? What thermal paste did you use to replace the one that had dried up? Make and model of the cooler used?

It the I7 coffee lake processor with a corsair water cooler. They gave me some grey compound but it dried up. I left it one there and mixed some white thermal compound with it. Used a stick to mix the dried stuff and it turned a darker grey. Now it runs at 26c at idle in a room that's about 69f. After mixing it on the processor I put the pump on it and worked it in a bit until the grease was no longer dry. I hope the new grease doesn't dry out, it came unmarked so I don't know what it is. It may have come with the processor. This was the Corsair with the full sized radiator and 3 fans. I think the processor dropped about 9c after applying new thermal compound. Again, not sure but dried up compound worries me.

 

[hotaru.hino]

Whether or not thermal paste dries out simply depends on if the chemicals used in making it remain stable with repeated thermal cycles. And likely what makes a formula more stable than another may also affect its thermal conductivity/resistance properties. For example, people knock on Intel's thermal paste, but that stuff is stable over a period of 5 years... because Intel expects people to not bother with checking the thermal paste for the life of the computer.

I mean, I don't claim to know the chemistry behind thermal grease, but in engineering of any sort, you almost never find an ideal thing that meets all requirements. There's going to be tradeoffs, and those two factors are what I imagine engineers who make thermal paste have to deal with.

It's not really a matter of "planned obsolesence" or not, it's more like "how can we cater to people who are paranoid about numbers?"

 

[CountMike]

There's no much chemistry to it, First it shouldn't be called grease because it isn't but modern paste uses silicone (not Silica) based compound which is a base to keep some very fine metal or ceramic particles in permanent suspension Those particles are real medium for transferring heat. Compound they are suspended in is neutral or even somewhat a heat insulator or just neutral and is not much if any help.
Beside being as good as possible heat conductors their size to be able to get into fine, microscopically small dips and scratches on the surfaces as well as their percent in compound is what mostly determines quality and effectiveness of paste, That doesn't change in time but quality pf suspension material does. If it dries out it shrinks and that may case particles not to be in full contact with surfaces and are not as effective any more.
Only way to actually check paste condition is to actually remove cooler and then you would have to change paste. Fortunately there are signs that paste may be compromised and that's raising temperatures and hot spots if you can detect it.

 

[Lafong]

Just curious if others have seen this.

My paste was applied 3 months short of 7 years ago. That is the longest I've ever gone.

I have no idea what it looks like and have no intention of finding out.

All I do know is that temps are totally unremarkable....the same as they were a day after the paste was applied.

Noctua NT-H1 with a Noctua U9S on a 6600K CPU.

 

[geofelt]

If I found rising cpu temperatures and no obvious cooler issues like fan not working only then would I check the paste.
Over many many years, I have yet not found the need to do so.

 

[Alan Alan]

There's no much chemistry to it, First it shouldn't be called grease because it isn't but modern paste uses silicone (not Silica) based compound which is a base to keep some very fine metal or ceramic particles in permanent suspension Those particles are real medium for transferring heat. Compound they are suspended in is neutral or even somewhat a heat insulator or just neutral and is not much if any help.
Beside being as good as possible heat conductors their size to be able to get into fine, microscopically small dips and scratches on the surfaces as well as their percent in compound is what mostly determines quality and effectiveness of paste, That doesn't change in time but quality pf suspension material does. If it dries out it shrinks and that may case particles not to be in full contact with surfaces and are not as effective any more.
Only way to actually check paste condition is to actually remove cooler and then you would have to change paste. Fortunately there are signs that paste may be compromised and that's raising temperatures and hot spots if you can detect it.

Yeah, we called it grease in the electronic service business, it was slang for thermal compound. It seemed a lot easier to say I gotta clean up this greasy mess when you got it all over the place. I worked on big power amps with lots of big transistors. Unfortunately the original compounds were chalk mixed with greasy paste that dried out. I never really knew if the amps blew because the thermal compound dried out but suspected it could. Some of the early heat conductors used shale. I think it was a rock that peeled off into very thin layers. Nowadays they use silpads. I think they lay down a net like fabric and apply silicone on it and flatten it out to the thickness of the fabric by dragging something flat over the fabric. After it dries it is spongy like silicone and really works good. I thought the processor would come with a thermal pad already attached. Probably a bad idea for one reason or another though.

 

[CountMike]

Yeah, we called it grease in the electronic service business, it was slang for thermal compound. It seemed a lot easier to say I gotta clean up this greasy mess when you got it all over the place. I worked on big power amps with lots of big transistors. Unfortunately the original compounds were chalk mixed with greasy paste that dried out. I never really knew if the amps blew because the thermal compound dried out but suspected it could. Some of the early heat conductors used shale. I think it was a rock that peeled off into very thin layers. Nowadays they use silpads. I think they lay down a net like fabric and apply silicone on it and flatten it out to the thickness of the fabric by dragging something flat over the fabric. After it dries it is spongy like silicone and really works good. I thought the processor would come with a thermal pad already attached. Probably a bad idea for one reason or another though.

Shale (Liskun, Mica) is primarily an electrical insulator that can take high temperatures and pressure. Once widely used even for spark plugs.
Thermal Grizzly makes some thermal pads, based on carbon fiber for use on CPUs and those can give run for their money with most pastes while not sticky and are reusable.

 

[Alan Alan]

Shale (Liskun, Mica) is primarily an electrical insulator that can take high temperatures and pressure. Once widely used even for spark plugs.
Thermal Grizzly makes some thermal pads, based on carbon fiber for use on CPUs and those can give run for their money with most pastes while not sticky and are reusable.

Come to think of it, they were called Mica insulators. I found out they were made of Shale and thought amazing , we could even split the Shale into thinner layers. Usually when we accidentally broke one and found out. Thermal Grizzly huh, I'll keep it in mind. The Louis expedition said they could shoot a Grizzly bear right in the heart and that didn't stop em. lol The legend lives on.

 

[CountMike]

Come to think of it, they were called Mica insulators. I found out they were made of Shale and thought amazing , we could even split the Shale into thinner layers. Usually when we accidentally broke one and found out. Thermal Grizzly huh, I'll keep it in mind. The Louis expedition said they could shoot a Grizzly bear right in the heart and that didn't stop em. lol The legend lives on.

Off focus but there's a legend that someone used frozen mercury in a rifle to kill a polar bear with it.

 

[Alan Alan]

Off focus but there's a legend that someone used frozen mercury in a rifle to kill a polar bear with it.

Spose so kingfish. Squeezed it right out of the tuna. lol

 

[toooooot]

I dont. On my PC, I dont.
I always replace it when someone brings me to fix it and I know device is old.
But I do not do it on my devices for few reasons:
First, I use the best paste which will not go dry in many years.
Second, I know I applied it well because I usually test new rigs under heavy use.
If temp is alright there is no need to check it.

 

[Alan Alan]

I dont. On my PC, I dont.
I always replace it when someone brings me to fix it and I know device is old.
But I do not do it on my devices for few reasons:
First, I use the best paste which will not go dry in many years.
Second, I know I applied it well because I usually test new rigs under heavy use.
If temp is alright there is no need to check it.

It seems to work even when it's dry. It's like a thin evenly spread grey chalk. Imagine the compound can be dry as long as there is an even coat after it dries. I think what is left is the thermal interface. Once separated it must be cleaned and reapplied or it wont conduct heat as well since the remains wont line back up. I only open mine to do a board swap. It now runs at 26c but I don't know what it was beforehand. So I don't know if new compound lowered the temp.