Once the correct voltage supply had been ensured, we fired up the computer. Its extremely quiet operation was particularly striking - neither the pump at the base of the PC nor the fan made any noise whatsoever. To perform our test, we started the usual benchmarks such as 3D Mark 2001, Sysmark 2000 and Quake 3 Arena. After about 20 minutes the computer crashed. We found that a great deal of heat was being generated inside the PC case, which was partly due to the absence of a case fan. The temperature on the CPU surface was - according to BIOS and contact-free laser measurement - approx. 45 degrees. This means that the cooling efficiency of the Koolance water cooler is significantly less than with a conventional cooler, which consists merely of the traditional heat sink combined with a fan. As a point of comparison on the subject of traditional coolers, readers may wish to refer to our recent review of 46 coolers:
The reason for the system crashing was, however, not the processor, as is so often the case, but the graphics card. At a temperature of 59 degrees on the underside of the graphic chip, the otherwise stable GeForce 2 GTS simply ceased to run. Further tests also produced the same outcome - the cooling efficiency of the Koolance system is so poor that the PC crashed after about 20 minutes of operation. We observed the following: the cooling water heats up successively per time unit until the graphics card stops working. To get to the bottom of this problem, we painstakingly stripped down the cooling system into its individual bits and pieces.