Excuse the l337 speak – it was very cold and artless of us. Still, you can’t pardon away the sleet appeal of strapping some coolness to your video card. It sure has Ron Prouse shivering in delight and his eyes leaking cloud juice.
The assumed prerequisite for this mod is to have a video card with the four holes around the perimeter of the GPU -- to aid in the mechanical 'attachment' of the cold-plate. The same process can be achieved on any processor by using thermal adhesive, however that will mean that everything is permanently attached, and the lifespan of the video card will be determined by the longevity of the other components. The method used here allows for the Peltier (TEC) and cold-plate to be removed for use on another video card, or for replacement should the card out-live the TEC. The water block is also kept separate, so that the video card can be removed from the motherboard without having to drain the cooling system.
ABOVE: Perfect allignment is essential.
The cold-plate is the most important component, and getting the fit right is critical. It must be centred over the GPU, with the four 2mm holes drilled and tapped in perfect alignment with the card. Using a drill-press is the easiest method of ensuring the holes are perpendicular on both vertical axes, and help guarantee the cold-plate will screw down onto the processor surface with even pressure.
ABOVE: Control condensation hotspots.
Insulating the GPU will help in controlling condensation, and consists of two components: some 3mm-thick neoprene rubber (wet-suit material), which is easily obtained -- a spare 'soft' stubby holder will do; and some non-conductive Artic Alumina thermal epoxy. The neoprene is cut to form a square 6mm wide 'gland', or gasket, to fit around the GPU and the four mounting holes, which is then attached to the PCB using the thermal epoxy.
ABOVE: Make sure there are no air gaps.
With the gasket in place, use either dielectric grease or RTV Silicon to fill any air gaps within the enclosure where condensation (or ice) might form, making sure to include the screw cavities. Unlike a CPU, a GPU is hard-wired into the PCB, so corrosion of connector pins due to moisture is not an issue -- the objective here is to prevent water build-up that might trickle off elsewhere with devastating results.
ABOVE: Make it firm, but not too tight.
Apply thermal grease to the GPU surface, and attach the cold-plate, making sure to tighten the screws evenly in an 'X' pattern. Be careful not to over-tighten the screws and cause damage to the GPU die -- a touch more than finger tight is all that's required to make sure that the two surfaces are in firm contact. Finally, apply several thin layers of RTV Silicon around the outer gasket / cold-plate joint.
ABOVE: Insulation is also needed on top.
The top of the PCB also needs to be insulated, using more neoprene rubber glued on with Artic Alumina thermal epoxy. The rubber should cover all of the GPU connections, and be at least the same dimensions as the cold-plate, or larger. Again, the intention is to eliminate any air pockets that might trap condensation. Any bare connectors, such as the 'legs' of the RAM and BIOS chips, should be protected with RTV Silicon for the same reason.
ABOVE: Use thermal expoxy to attach.
With the cold-plate secured, attach the TEC to the centre of the plate with thermal epoxy -- hot side up! The eight-amp Peltier used here is 'un-potted', so the sides will need to be filled with epoxy -- by sealing in the edges of the TEC you are in effect potting it and the life of the unit will be extended, especially if it is done under vacuum. If possible, it is better to purchase a TEC that is already potted -- Silverprop sell an excellent unit, but were out of stock at the time of writing.
ABOVE: Remember the thermal probe.
The TEC wiring needs to be supported and protected, so it has been covered with PVC tubing. As an afterthought, a thermal probe has been glued onto the cold-plate so that temperatures can be monitored during use -- in hindsight, a better method would be to glue it to the side of the GPU before assembly, and then route the wires out through the neoprene gasket. As in step six, all exposed connectors and joints should be covered with RTV Silicon.
ABOVE: Bolt together water-block brackets.
The next task is to fabricate the mounting brackets for the water-block. Using the OEM HSF retention holes is the easiest path, and by using 'long' nylon nuts, washers, spacers and 3mm screws from JAYCAR it is a straightfor
Issue: 133 | February, 2012