Liquid-Cooling for Dummies: Taking the Radeon X1900 XTX to the Limits?
Even though the PCB of the Toxic Radeon X1900 XTX with water-cooling does not differ from any other on the market, the actual heart of Toxic is a specially designed cooling system that is not available in the retail and that should ensure that the Blizzard is silent and overclockable.
One thing that we discover when we take a look at the product is that liquid-cooling only applies to the graphics processor. The memory is cooled-down using tiny radiators, which are attached to the devices using thermal glue. This does not seem to be a huge problem, as according to Samsung Electronics every GDDR3 K4J52324QC-BJ11 memory chip consumes up to 2.73W, not a lot isn’t it? Moreover, Samsung claims that the threshold temperature of its chips is 125° C, which will hardly be achieved under normal conditions. Still, some of computer enthusiasts may want to use a bit larger radiators on the memory, something we will discuss a little later.
The majority of water-blocks available on the market are made of copper. The copper is known for very quick absorption of thermal energy and has proved itself as the best material for water-blocks. For some reason, Thermaltake and Sapphire decided to use aluminum water-block for the Toxic Radeon X1900 XTX with liquid-cooling technology, which may mean that the cooling efficiency is not the highest possible, something which a buyer of a premium product may hope for in expectations for further overclocking.
The organization of the liquid cooling is pretty simple, but that’s the idea behind the Toxic: to provide a very simplistic liquid cooling. The coolant is circulated with a 12V mini pump developed by Thermaltake, is pumped into copper tubes surrounded by radiator which is cooled-down by airflow of a fan that can rotate at 2000rpm or 2500rpm depending on the setting. It should be noted that the fan exhausts heat outside the computer case.
We should point out that the cooling solution used is generally the TideWater mini from Thermaltake. While we do now know its maximum thermal performance, we reckon that the original TideWater could dissipate up to 120W from the GPU and the difference between it and the mini is the smaller size of the radiator used by the latter. As reported, the Radeon X1900 XTX has thermal design power of 90W, therefore, Thermaltake TideWater mini should be able to cool it down without much problems at default speeds, but it hardly has significant threshold for overclocking. However, we do not think we should blame Sapphire for this situation. The retail versions of the Toxic Radeon X1900 XTX with liquid-cooling technology take 2 slots. With larger water-pump it would take 3 spare slots, which is not an option for many computer enthusiasts.
While installing the water pump in a free add-in-card slot is generally a nice idea, this will not work for micro-ATX computer cases. Moreover, it will not work on the vast majority of ATI CrossFire Xpress 1600 (RD480) mainboards, as the main PEG x16 slot for graphics cards is the “lower one”, hence, either there is not a lot of space below, or the tubes for liquid will touch memory heat-spreaders, which is not good at all, as the rubber can be damaged by high temperatures.
All-in-all, if you want to get Sapphire’s Toxic Radeon X1900 XTX, make sure you have the lowest PCI slot available and that water tubes do not touch memory radiators. Also you should check from time to time whether the exhausting turbine is not filed with the dust, as if your PC tower is standing on the floor, there will be quite a lot of dust on the bottom of your case. Finally, you should make sure that the airflows inside your case can cool-down PCB of the Toxic graphics card: unlike the default cooling system, Thermaltake’s TideWater mini cools only the GPU and does not take any heat away from memory and PCB.