By: Greg Zenger
A guide how on to watercool your Radeon 8500.
ATI's Radeon 8500 was, and still is a popular graphics card. With the introduction of the Geforce4 and most recently the Radeon 9700 Pro, the full retail version of the Radeon 8500 can be obtained at an excellent price. With cooling modifications and perhaps a volt mod, (which I have yet to do successfully) the Radeon 8500 can be overclocked quite a bit. Whether you plan to water-cool this card because you already have it and don't wish to upgrade quite yet, or you just don't have the money for a new card, this article should guide you through the process.
Mounting Holes! Come out, come out wherever you are...
Upon first examination of this card you will notice that there are no mounting holes. However, ATI's newer cards, the 9000 and 9700 Pro, have the holes. Well, this leaves us with three options: (1) Abandon the project, (2) Use some sort of clamp, or (3) Use thermal epoxy to attach the water block. Obviously, we aren't going to be turned away by the lack of a few holes, so we are left with options 2 and 3. Both of these would work, however I chose the slightly more permanent option, option number 3.
There are many water blocks available for cooling Geforce cards, but none for cooling the Radeon due to of its lack of mounting holes. I was already ordering my CPU water block from Danger Den, so I decided to order one of their Geforce 3 Blocks. At the time I purchased my water blocks, Danger Den was only offering two GPU blocks, one with barbs that protruded out the side, and one with 90º angled barbs. The clear advantage to the lower profile block with straight barbs is that it will not block more-than-one/any PCI slots. The other block, which is the one that I chose, blocks 2 slots. Now don't make any false assumptions and call me dumb, because I have a very good reason for selecting the block that obstructed the PCI slots. I wanted to attach heat sinks to the memory chips on my Radeon, and the low profile block's barbs would not have left enough space for heat sinks on two of the memory chips; the 90º angled barbed block left the required amount of clearance.
Removing the Heat Sink is probably the one of the most difficult step to modding a graphics card. There are several ways to do it, so feel free to use whatever method you like. I prefer the 'Freezer Trick' method: Place your graphics card in an antistatic bag, and seal it up tightly. Place the card into your freezer for 25-45 minutes. The cold temperatures inside the freezer cause the thermal epoxy holding the HSF in place to become brittle. Now, remove the card and place a credit card, driver's license, phone card, ATM card, or the like, between the graphics card and the HSF. Now place a screwdriver between the card and the HSF and give the screwdriver a little twist, move the screwdriver to another part under the HSF, and twist some more. Eventually, the HSF will pop off leaving a mess of leftover epoxy on the GPU. With a little bit of scrubbing, rubbing alcohol will clean this up nicely.
Once you have cleaned the GPU core it is time to mix the thermal epoxy to hold it on. There are different types of epoxies available. I used the Arctic Alumina Thermal Epoxy mixed with a little bit of Arctic Alumina Thermal Compound. Because the Arctic Alumina Epoxy is so strong, I used a 1:1:1 ratio of AA Epoxy Part A, AA Epoxy Part B, and AA Thermal Compound respectively. This somewhat weakens the epoxy's grab so it would be removable later. Once the parts are mixed you have approx 3-5 minutes of time to spread it smoothly onto the GPU and press the water block in place. Hold/clamp the block in place for a few minutes to let the epoxy set up. If you plan to attach heat sinks, now would be a good time to do so. I made my heat sinks from a Pentium-90 heat sink that was cut into eighths by a band saw.
After the epoxy has set for 12-24 hours it should be strong enough to hold. Attach your tubes and clamp them down with some hose clamps or zip ties then stick the card into your computer. I use Power Strip to experiment with different core and memory settings, and when I find settings that I am happy with I flash them to the card so it always has the overclock. I have been able to get my speeds past 300/305 but I run the card at 290/290 to guarantee stability.
I wish you luck with your water cooling and overclocking.