What is a break-in period for thermal paste?

[Hyperman3218]

I was taking a look at how to apply thermal paste onto a CPU today and I saw something called a break in period. http://www.arcticsilver.com/pdf/appmeth/int/vl/intel_app_method_vertical_line_v1.1.pdf

Could you please explain to me what a break-in period for thermal paste is? This is my first build. And also if you could also provide me with some info that'll be helpful to a first-time builder like me please leave some tips and application methods. Thanks in advance.

 

[SinxarKnights]

Despite what most people seem to think, there are only a small handful of paste that has a curing/burn-in period.

With AS-5 the process takes somewhere around 200 hours of use and thermal cycles to reach full thermal conductivity. I think it has something to do with the silver particles lining up properly or something like that. However the difference between a fresh application and fully cured AS-5 is minimal (typically between 0.2c - 3c difference). MX-1 Is similar but has a different consistency.

There are other types of TIM that a new builder may want to avoid. Any type of adhesive TIM or any that is extremely thin or runny can cause issues for a first time user. These generally require a curing time (just like glue) to even be used and can be extremely difficult to remove without damaging the CPU.

 

[Gam3r01]

That is the time it takes the paste to cure.
This curing cycle involved heat generated from use, as well as cooling cycles. (System turned off then on later)

I wouldnt bother worrying about cure periods, or pastes that have them.
Example: Arctic MX-4 is a great paste without cure time.

As for application, it varies processor to processor, and there no one "Correct" way to apply it. I like the pea method.

 

[synphul]

Here's an article on different ways to apply thermal paste.
https://www.pugetsystems.com/labs/articles/Thermal-Paste-Application-Techniques-170/

The most popular methods are the pea sized dot in the middle, vertical line (usually with intel cpu's) and x-shape. The goal is to get a thin even coat when the cooler is pressed to the cpu. Too little paste can leave small gaps while too much paste can start causing an insulating effect. Ideally the cooler base and lid of the cpu would be perfectly pressed against one another but it's not realistic. The paste fills in all the microscopic pits and valleys and makes for more efficient heat transfer.

Some pastes have a break in period, others don't. A break in period is usually caused by thermal cycling of the machine being on (hot) and turned off (cooled to room temp). During that time the heating/cooling of the paste can help it further spread, fill the tiny gaps and 'cure' between the cpu and cooler base. Running the pc for 30min or so and turning it off for 20-30min to cool would be considered a 'cycle', some people use stress tests while the pc is on to accelerate the process. For most people who turn their pc on when they use it then turn it off when they're done, the break in period will happen on it's own and it only takes a few times for the paste to reach it's maximum efficiency.

 

[iam2thecrowe]

I dont use AS5 anymore for that reason, it has break in period. Other pastes like noctua nt-h1 are as effective, and have no burn-in period.

 

[Hyperman3218]

Despite what most people seem to think, there are only a small handful of paste that has a curing/burn-in period.

With AS-5 the process takes somewhere around 200 hours of use and thermal cycles to reach full thermal conductivity. I think it has something to do with the silver particles lining up properly or something like that. However the difference between a fresh application and fully cured AS-5 is minimal (typically between 0.2c - 3c difference). MX-1 Is similar but has a different consistency.

There are other types of TIM that a new builder may want to avoid. Any type of adhesive TIM or any that is extremely thin or runny can cause issues for a first time user. These generally require a curing time (just like glue) to even be used and can be extremely difficult to remove without damaging the CPU.

I dont use AS5 anymore for that reason, it has break in period. Other pastes like noctua nt-h1 are as effective, and have no burn-in period.

Thanks, I'll keep that in mind!