How thick should thermal pads be?

[testtube5]

I'm looking to replace the thermal paste and thermal pads on my GTX 760 (Since I can't buy a new Graphics Card right now I'm trying to get as much lifespan as possible out of my 760; and may just use it until it dies).

I'm noticing that there are several thicknesses, from 1mm up to 5mm as far as I saw.

How thick should they be? As thick as possible or do they have to be a specific thickness for a specific component?

 

[Eximo]

As thin as will work ideally. Annoyingly the best way to tell, is to take the card apart and measure the uncompressed thickness of all the pads.

If they are fully squished, then just go up a thickness to make sure of contact.

You can probably get away with only replacing the thermal compound, the pads can often be re-used a few times.

 

[TJ Hooker]

You want them just thick enough to span the distance between the two components that are to exchange heat. For a graphics card, this would typically be the distance between the VRM/Memory modules and the baseplate/heatsink. So no, not as thick as possible. Measure the ones that are currently on there and get the same thickness.