This week, Thermalright announced a new revision of the Thermalright Silver Arrow IB-E Extreme cooler, tacking on a "Rev. B" at the end and creating the Thermalright Silver Arrow IB-E Extreme Rev. B. The claim to fame for this heatsink, outside of its massive size and 320W capacity, is the offset heat pipe and fin array also around the topmost slots, giving users more freedom to choose the memory they want without sacrificing cooling performance.
First, its size. The IB-E Extreme Rev. B measures 155x130x163mm (LxWxH). The CPU cooler itself features a mirror finish, nickel-plated copper base along with eight 6mm heatpipes, which meander through both of the heatsink towers. Not only is the heatsink large, but it is also has a lot of mass, weighing in at 850g without fans. The offset design should allow for taller memory to fit underneath, as well as giving a bit more room for the topmost expansion slot on the motherboard.
The heatsink includes two TY-143 fans, which run from 600~2500 RPM ±10 percent. The PWM-powered dual ballbearing fans can push 31.4~130 CFM with a static pressure of 0.32~3.0mm H20 with noise levels said to be in the 21~45 dBA range. Using higher static pressure fans like these is a good match considering the fin gap is pretty tight at 2mm (with 0.4mm thick fins).
The Thermalright Silver Arrow IB-E Rev. B heatsink will support Intel sockets 775, 115X, 1366, 2011, 2011-v3 and 2066. For AMD, only socket AM4 is listed, but it's possible AM3+ on down is supported as well, since its predecessor supported them.
Neither pricing nor availability was listed at the time of writing, but it is expected to be in the ballpark of the outgoing Silver Arrow IB-E, which is currently $99.95 on Amazon.