Some Intel Skylake CPUs are literally bending under the weight of heavy aftermarket CPU coolers. Or, more specifically, the pressure exerted by some coolers seems to be causing damage to Skylake chips. The likely culprit: Intel used a thinner wafer on Skylake CPUs than past chips. According to Intel, the thinner substrate is still rated for the same 50 pound static load, but this issue is definitely real: we've experienced it ourselves.
Left: Haswell CPU.
Right: Skylake CPU.
Note the thinner wafer on Skylake.
Recently, while moving a Skylake i7-6700K between two systems, our colleagues at Maximum PC experienced this exact bending issue. The damage was caused by installing either an EK-XLC Predator 240, Deep Cool _ or Corsair H90 liquid cooler. We thought too much force had been applied to the chip by installing one of those coolers with an electric screwdriver. It's still possible that the screwdriver applied a damaging amount of force and the damage was user error, but we've never experienced a similar issue on older Intel CPUs with thicker wafers.
PC Games Hardware in Germany first reported on the problem on November 30, and several aftermarket cooler makers have commented on the issue. Arctic recommends removal of the CPU cooler for transport (if the system is dropped, a heavy cooler could apply a damaging amount of force to the chip). The pins, motherboard contacts and even the CPU itself can be bent, especially if your PC experiences any bumps.
EK and NZXT told Tom's Hardware that their coolers are fully compliant with Intel's force regulations, but both recommended against using older generation coolers that may apply too much pressure. Scythe has said on its support website that it is reducing the mounting pressure of its coolers for Skylake by adjusting the screw set. It will be sending a new set of screws to its customers free of charge.
Intel told Tom's Hardware it's investigating the issue. We've reached out to Corsair with a request for comment and will update when we hear back.
If you're installing a Skylake CPU anytime soon, be gentle.
A number of manufacturers have released official statements on this issue. Intel itself has said that "the design specifications and guidelines for the 6th Gen Intel Core processor using the LGA 1151 socket are unchanged from previous generations and are available for partners and 3rd party manufacturers. Intel can’t comment on 3rd party designs or their adherence to the recommended design specifications. For questions about a specific cooling product we must defer to the manufacturer."
Cryorig says that currently none of its "heatsinks have displayed this problem, either through media reports, third party sales channels or internal testing. CRYORIG heatsinks are fully compatible with socket 1151 processors, and follow specifications set forth by CPU manufacturers. But as a note of precaution we suggest users to lay their PC system flat (with the heatsink in a vertical position) whenever they are transporting their PC system."
Cryorig has however provided some suggestions as to what may be causing the problem. "A) High mounting pressure from the CPU heatsink mounting system, with no flexibility in the system. B) Increased directional force created by the weight of the heatsink and movement of the PC chassis." The company goes on to state that its heatsinks are safe because of its high tensile strength mounting systems.
Scythe quickly announced plans to solve the problem. "Japanese cooling expert Scythe announces a change of the mounting system for Skylake / Socket 1151 on several coolers of its portfolio. All coolers are compatible with Skylake sockets in general, but bear the possibility of damage to CPU and motherboard in some cases where the PC is exposed to strong shocks (e.g. during shipping or relocation). This problem particularly involves only coolers which will mounted with the H.P.M.S. mounting system*. To prevent this, the mounting pressure has been reduced by an adjustment of the screw set. Of course, Scythe is going to ship a the new set of screws to every customer completely free of charge! To apply for the free screw set, please send your request via e-mail to email@example.com or use the contact form on our website."
According to Tom's Hardware, Corsair says that there is "no danger" to your CPU when using its liquid cooling products thanks to the design of its pumps, which are within Intel and AMD's specifications.