The premise behind the Silent Boost heatsink series is quiet cooling. The unique fans Thermaltake use, relate directly to the modified fans developed a couple years ago by Andy Lemont. Mr. Lemont discovered that horizontal slits in the fan casing could help to decrease fan noise by several orders of magnitude, and worked for short time promoting a heatsink adapted to this technique. The fan frame features a series of four 1.5mm x 32mm slits cut from what would normally be a solid surface. The slits allow air to be drawn in by the impeller at different locations, with the end result being a slightly lower pitch of sound from the 2450RPM fan.