Sapphire Radeon HD 4850 Vapor X review

Sapphire Radeon HD 4850 Vapor X reviewAuthor: Luka RakamaricDate: 27 Apr 2009
Sapphire has been experimenting with different coolers for quite some time now. During the last year’s CeBIT, we spent some time playing with their Toxic cards that use the same cooling method as the card we have before us today. However, the new model is based on the next generation GPU, the RV770. Usually we start the review with the overview of the GPU, but since the RV770 is a chip present on the market for quite some time, we will first concentrate on the cooling solution of the card.The cooler is pretty much a standard size dual slot cooler, with an 8 cm axial fan that is blowing air on the aluminum fins connected to the base of the cooler. The base is what separates this cooler from all others. Instead of a standard mono block of aluminum or copper, this base is hollow and partially filled with water. The idea is to use the vaporization energy of water to transfer heat from the GPU to the fins. Because water evaporates at 100 degrees Celsius at standard atmospheric pressure, and the GPU’s desired operating temperature is somewhat lower than that, the pressure inside the base is lowered so water evaporates more quickly. The liquid water on the side in contact of the GPU takes on energy in form of heat and becomes vapor. It then travels to the other side where it condenses, and releases heat to the fins in the process. It functions in much the same way as a heatpipe does, but with a lot more surface area to transfer the heat and direct contact with the heat source.The 8 cm fan is responsible for the very low noise of the card, which even under full load doesn’t overcome the noise of the average PC. However, our watercooled test platform is extremely quiet, so the noise of the card is noticeable, which makes it not that great for silent PCs. The rear bracket has a mesh through which hot air can travel outside the system case, but the cooler itself is not forcing all the air through the mesh. This design approach raises the system case temperature and makes cooling even more inefficient, not only for the graphics card but all other system components.
Source : http://it-review.net