Detailed How-TZo – Murray Turner (Murdawg)
The 9700 pro has a very good heatsink compared to most other video cards on the market, but for some people very good isn’t good enough and there is always ways to improve on this.
There is a shim protecting the core under that heatsink and many have claimed that it is something that can reduce the overclockability of the core.
So today we are going to:
Once again this will void your warranty and I am no way responsible for your actions or the result of you attemping this.
This 9700 Pro I’m using turned out to be a very good overclocker before any modifications. It would run a complete 3DMark2001 test at 375 core 345 ram. Using very cold air, (-20c or more) it would complete the tests at 390 core 355 ram.
Here is the heatsink for the Radeon 9700 Pro
Two clips on the back of the videocard attach the heatsink to the card. You first need to take a pair of plyers or tweasers or chopsticks or anything else that will that will let you squeeze the clips together so you can push them through the hole and thus detach the heatsink.
I had another person help me hold the card and try to squeeze and push at the same time.
It might take a little bit of work but they will come off fairly easy.
Once you have the fan off, turn it over to see the kind of contact it made with the GPU core. (My particular card had a yellow thermal pad and was actually making a very good connection which would explain my decent stock overclocking.)
Scrape the thermal pad off the heatsink. I usually use something hard and plastic to avoid scarring the heatsink and having to do a lot more lapping to remove the scratches.
To get the shim off, I used the thinnest bladed utility knife I could find.
Using the very end of the blade, start gently pushing in and prying up.
As I moved around the outside edge and was able to get more aggressive in my prying, the shim popped off of the core. As you can see it is glued in strips on the four sides.
With rubbing alcohol and Q-tips, clean up the core and any excess thermal paste. Don’t worry about the glue on the card because it is sunk below the core and wont affect the contact of the heatsink on the GPU core.
If you have time, it never hurts to lap the heatsink while it is off. The heatsink included with my 9700 Pro was fairly flat so I just continued until all the black paint was wore off and polished it a small amount. For directions on how to lap the heatsink just check “How to Lap a P4” article and follow the general guidelines.
Apply AS3 onto the core of the gpu and reapply the heatsink. Be very careful now. You don’t have the shim protecting the core any longer, so if you push too hard on any of the edges the heatsink could crush one of the corners and kill your video card.
With no extra case fans or fans actually blowing on the video card, the 9700 Pro will now do 3DMark 2001 at a stable 401 MHz at room temps. That’s up from 375MHz.
The nice thing is it must be transfering the heat better because both the heatsink is warmer and it is able to be left at 398mhz all day long with no extra fans blowing on it. That is the bigger improvement of the two.
Ed. note: We suspect the shim is not the real culprit here. A thermal pad was replaced with a much better heat conductor, AS3. However, because the shim is designed to accomodate a relatively thick thermal pad rather than a thin layer of AS3, you can’t just leave the shim in place because it is likely you’ll end up with poor or even no contract with the GPU.