Hello. I am curious what to do with my GPU thermal grease. when I was changing CPU thermal compound I've seen that GPU grease looks like a rubber square (and it feels like that when i touched an edge of it). I haven't changed it because GPU surface is not flat as CPU. Should I change it and if so, how to do that because it is not flat.
That is not thermal grease or paste on the GPU but it's double sided thermal tape.
So if you have some after market thermal tape on you, you could always cut it up to size and change it.
Or you can use thermal paste too but you need to be careful since you say the GPU is not flat like the CPU, which is slightly odd, cos usually they are flat only difference is the heatsink may not be flat but the parts that come in contact with the heatsink are flat.
So you need to apply thermal paste on the parts and then put the heatsink back on after removing the thermal tape....