Caution: heat sync metal may be delicate

[smirk]

Well, I just replaced my stock 2.8 GHz CPU in my 5,1 with a faster one, and thought I'd briefly share a mistake I made in case it helps anyone else.

When removing the old thermal compound from the heat sync, I used a coffee filter because the Arctic Silver instructions say it is acceptable to use and is lint free. However, it seems to have scratched up the copper on my Mac Pro's heat sync quite a bit. I didn't feel like trying to figure out how to "lap" the heat sync to smooth it back out, so I proceeded with my installation and it seems to be working -- but I'm not happy about the scratches.

Perhaps a micro fiber cloth would have been better.



Edit: I guess I don't know for sure that the coffee filter caused it, but I did wipe in a circular pattern just like that.

 

[leon771]

Thermal compound will fill in the micro scratches. I wouldn’t be worried about it at all.

 

[h9826790]

Well, I just replaced my stock 2.8 GHz CPU in my 5,1 with a faster one, and thought I'd briefly share a mistake I made in case it helps anyone else.

When removing the old thermal compound from the heat sync, I used a coffee filter because the Arctic Silver instructions say it is acceptable to use and is lint free. However, it seems to have scratched up the copper on my Mac Pro's heat sync quite a bit. I didn't feel like trying to figure out how to "lap" the heat sync to smooth it back out, so I proceeded with my installation and it seems to be working -- but I'm not happy about the scratches.

Perhaps a micro fiber cloth would have been better.



Edit: I guess I don't know for sure that the coffee filter caused it, but I did wipe in a circular pattern just like that.

AFAIK, that copper plate on cMP heatsink is not mirror like from the beginning. And circular “scratch” won’t affect the cooling performance, but may actually help to spread the thermal paste (Noctua explaination about why their heatsink is not come with mirror like contact plate).

If you want to, you can always apply metal polisher to make that mirror like (a very common mod for laptop guys). However, as long as it’s working. I personally won’t suggest anyone to try to “fix” that. The performance difference most likely practically zero anyway.

 

[smirk]

Thanks guys, that's good to know. I had thought that scratches would prevent good contact and make it run hot.

After running Prime95 for an hour or so, it seems to be hovering around 85C. Apple's cooling scheme is funny; it ramps up the fans just slightly until the temp drops a couple degrees, then it immediately drops the fans back to normal. But so far it hasn't ever gotten warmer than 85C.