Quote Originally Posted by Phil The Greek View Post
I used a cpu pot like the video BUT I had to heat it up to 140 celsius and leave it for at least 4~5 min. till the silicone came soft and able to cut with the razer(probably the video is fake and the HS is already removed).
The thing is that the symptoms appeared before removing the HS.
first time (on MOA) we used CPU Pot and arround 100° to do the removal, core degraded

Quote Originally Posted by slamms View Post
On MOA final 120 degress and 1-2 minutes, core degraded too.
second time we used Heat gun set at 250° directly to the Heatspreader, core degraded

Quote Originally Posted by SF3D View Post
I try to be useful here

This behaviour is because you need to have some buffer between pot and die.
I found out, that if you have direct contact between the large copper block (base of GPU pot),
results will get worse especially in heavy load.

When you have this kind of contact, which is actually super good,
you will not be able to transfer heat fast enough out of the die.
This is the reason you will loose that much MHz. It will propably cause the instant lock up in the beginning of some test.

Nvidia stock thermal paste is shin etsu, which is not good paste in general, but not bad with ln2 either.
It is working pretty well in heavy load and it is possible to transfer that huge heatload to HS.
When you have some good thermal paste in use, you will now be able to transfer that heat from HS to GPU pot.

This way the temperature of GPU is higher and when you have enough voltage they will run well.
Without HS you will get too cold very easily and face some other cold related issues as well.

I actually tried quite thick copper plate between pot and GPU HS and it worked well.
That was my 1455MHz unigine run with that certain DCII card.
The card was a lot easier to hold in correct temperature range that way.

So, my point was that keep the HS on. Keep the GPU warm enough and give enough voltage for it.
Unfortunatly it's not the answer to set back the Heatspreader (OCz Freeze between GPU and HS) still degraded core.
Your point is really interessting and we will test next time the differences with some copper plate.

Later in times of the HD 5870 Lightning we used a Copper plate too, but not for buffering, more for getting more distance between PCB and Pot.

But I think the matter of the degrading cores are to high Temperatures during the removal