Summary: The Zalman CNPS10X Optima heatsink is a fairly standard tower cooler in most respects; it offers pretty good thermal performance, accomodates a front and rear fan and has an exposed copper heatpipe base.
Conclusion: The Zalman CNPS10X Flex is certainly worth considering for LGA1366 CPUs. On LGA1156 or Socket AM2+, the cooling power of the heatsink was comparatively poor no matter which fan we used. However, on LGA1366, the Flex was more interesting.
Summary: The Zalman CNPS10X Flex heatsink ships without any fans, so users can install one or two 120mm fans of their own choosing. In all other respects the CNPS10X Flex is identical to Zalman's CNPS10X Quiet heatsink, so today's review is not going to be a huge departure from what we saw from the Quiet.