The Nexus XiR coolers combine some of the most advanced technologies in the market used for CPU coolers. Heat pipes, SkiveTek and ultra-thin fins combined with a real silent temperature controlled fan delivers ultimate performance which has never been this quiet before. XiR coolers are crafted out of the purest copper and aluminum materials. The heat sink covering the heat pipes and the copper base is made using SkiveTek technology. We have managed to apply the best technologies at the best position on the cooler. And the result is astonishing... The temperature sensor on the fan makes sure the fan speed is always at an optimal lowest speed. The speed can vary between 1500 and 2500 RPM creating a noise-output of an inaudible 15 dB(A) up till a still truly quiet 24 dB(A). You should really experience it yourselves; high-end performance and low-noise combined. The XiR cooler range is your best choice! ohh...before we forget. We put two orange LED in the fans center core...just for fun. Nexus XiR Cooler Specifications copper base 4 x 6mm copper heat pipes SkiveTek heat-sink copper fins ultra-thin fins temperature controlled fan universal application XiR-3500 copper edition Cooler specifications Universal application Dimensions   [LxWxH] Materials       Weight Heat pipe Intel 775, AMD AM2 754 939 940 106 x 122 x 111 mm 4.17x4.80x4.37 inch Pure copper base Pure copper heat pipe Pure aluminum heat sink Pure copper fins 736 gr / 25.96 oz 4 heat pipes of 6 mm / 0.236 inch diameter   Fan specifications Both the Xir-2300 and the XiR-3500 use the same fan so fan specifications are identical. Performance difference between the XiR-2300 and XiR-3500 is cause by the different materials used for the fins. The material of the fins does not influence the noise level of the cooler. Fan size Fan voltage Fan function Fan speed Fan connector LED's   Noise level 92 x 25 mm / 3.6 x 0.9 inch 12V temperature controlled by fan sensor 1200 to 2500 RPM (± 10%) 4-pin 2 x orange LED in fan center core Pure copper fins 15 ~ 24 dB(A)*   Noise level test When we test the noise level of our products we do this in an ISO-certified chamber and according to a prescribed set-up. Measurement is done using a Brüel & Kjær microphone. It is important to know that the background noise in an official noise test chamber is approximately 15 dB(A). These are the best possible conditions for these tests and hence you should always be aware when a manufacturer is claiming dB(A) values that are lower then 15 dB(A). Because how where they able to measure this? We provide the real figures, from the actual tests. Can it get any more reliable? Judge for your self.   Nexus provides the exact details of our noise level test as we feel dB(A) values are difficult values to compare as there are many ways of testing and calculating. In the market there are a lot of unrealistic dB(A) value-claims which are often calculated by means of extrapolation. This in fact does not give a realist view of the fans noise level performance. We provide the real figures, from the actual tests. Judge for your self.