Investigating Reports Of Intel Skylake CPUs Damaged By CPU Coolers (Update 4)

Reports have begun to surface of Intel 6th-gen (Skylake) CPUs and their corresponding motherboards being damaged from some cooling solutions. Some reports suggest that these chips have a weaker construction that can sustain damage when too much pressure is applied. A German tech website,, did some independent testing and determined that the substrate on Skylake CPU’s is thinner than that of previous generations. As a result, CPU coolers that apply high levels of pressure to the CPU and socket can sometimes damage both, according to the site.

Cooler Makers' Responses

We were first alerted to the issue by Arctic in a press release. The company made the announcement yesterday that it has verified that all of its CPU coolers are fully Skylake compatible following reports of possible damage. Arctic did note that due to the potential of being dropped in shipping, the company recommends removal of the CPU cooler for transport. Arctic even recommended that system builders have the end user install the cooler after shipping.

Scythe appears to be among the only companies affected so far. The company made a post on its support page noting that it will be redesigning the mounting mechanism for Skylake CPUs. The company said that its CPU coolers are “compatible with Skylake sockets in general,” but the H.P.M.S mounting system employed can cause damage if the PC is exposed to strong shocks sometimes caused by shipping. Scythe said the solution is a new set of screws that reduces the mounting pressure. Affected coolers include Ashura, Mugen 4, Mugen 4 PCGH-Edition, Fuma, Ninja 4, Grand Kama Cross 4, Mugen Max and Kotetsu. If you are using one of these coolers, Scythe will send a set of upgraded screws free of charge if you fill out this form.

We’ve reached out to a number of other vendors who provide cooling solutions for Intel CPUs, including Cooler Master, Corsair and NZXT. We’ve yet to hear back from Cooler Master and Corsair but NZXT had this to say:

All NZXT Kraken Series closed loop liquid coolers are fully compliant with Intel's socket 1151 mechanical force specification. The mounting system developed for NZXT's liquid coolers does not encounter the problems associated with either gravity that large fin arrays of oversized tower coolers have or with Skylake's changes in substrate and IHS thickness. 

Our older generation of large tower coolers (Havik 120/140) are mounting and pressure compatible with socket 1151, but we advise against using them with socket 1151 CPUs due to potential of force exerted on the socket by the weight of the cooler.

After publishing this article originally, we received a statement from EK Water Blocks regarding its product lineups.

All EK Water Blocks EK-Supremacy series CPU water blocks - including the latest –MX and –EVO variants - are fully complying with imposed Intel Socket H3 (LGA-1151) mechanical force limitation. The clamping force, created by our PreciseMount spring loaded mounting mechanism, is well within the allowed mechanical limitations. The design of PreciseMount itself prevents over-tightening and possible mechanical damage to either socket or the CPU packaging.

Older generation of (physically) compatible LGA-1151 water blocks with classic, undefined clamping force type mounting mechanism - such as Supreme LTX - requires special attention when attaching the water block. As a result the use of such water blocks is not recommended with the LGA-1151 socket CPUs.

Early Monday morning, Corsair replied with its official statement. It's the boldest statement yet from a manufacturer on this issue:

All Corsair coolers are designed strictly to the Intel and AMD specifications for cooler mass and spring force. Furthermore the compact nature of our pumps prevents dynamic forces such as bouncing from damaging the CPU socket. There is no danger to your CPU, Skylake or otherwise, from installing a Corsair liquid cooler to it and our hundreds of thousands of satisfied Hydro series customers since the Skylake launch are testament to that.

On Tuesday morning, Cryorig reached out to Tom's Hardware to weigh in on the situation. In a lengthy explanation, the company laid out its observations and confirmed that its own products are not showing any signs of damaging Skylake systems.

We at CRYORIG have the following information and statement to make, regarding the recent news and discussion regarding damaged PCB’s on Skylake CPU’s, which many in the industry believe is caused by abnormal heatsink mounting pressure during transportation of the PC system. First of all we want to assure users of CRYORIG products that currently no CRYORIG 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.

Based on the information and testing reports we currently have at hand, although CRYORIG’s own products did not show this problem, we have derived the following suggestions and insight into the Skylake PCB damage problem. From our observation the cause of the bent/damaged PCB is caused by the combination of two factors.

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.

In the cases that have been reported by media, it holds true that these issues have only been observed in “Pre-Built” systems. These systems have the heatsink installed before shipping, which are subjective to both point A+B. Thus if a heatsink already has high mounting pressure with no system of flexibility, heavy weight and is tossed around during shipping, then the force of the heatsink is possible to bend at the softest point. In this case the softest point is the Skylake PCB.

According to our hypothesis, then what makes CRYORIG heatsinks safe? In our own product line we have two different mounting systems. First is the MultiSeg on our heavier products, then there is the X-Bar and MultiSeg Light. The MultiSeg Quick Mount System uses a sturdy Medium Carbon Steel backplate. We chose the Medium Carbon Steel for it’s high tensile strength, which protects the mainboard from bending when using heavier heatsinks like the R1 or H5. In combination with a highly rigid backplate, the spring screw system is what provides the downwards-clamping mounting force. This combination of a tough frame and a relatively softer point of flexibility is the key to why CRYORIG products are not seen damaging the CPU PCB. When extra vector/directional force is exhibited on the heatsink (such as during transport), the softest point in the system always gives. In this case the spring screws will deform to absorb the extra external force, much like a suspension system.

In our lighter products, the X-Bar and MultiSeg Light mounting systems omit the rigid steel backplate for a 30% Fiber Glass PBT. The lighter weight of our H7/M9 and C7 heatsinks creates less stress on the mainboard, which is why the steel backplate is not needed. Also, using a Fiber Glass filled PBT has multiple benefits.

Material Modulus of Elasticity (The Higher the more Rigid)

30% Fiber Glass PBT       15.0 GPa Max

Medium Carbon Steel     213.0 GPa Max

        The Modulus of Elasticity for 30% Fiber Glass PBT is 15.0 GPa, while Medium Carbon Steel is 213 GPa. The combination of structural support and elasticity, allows these backplate system to still have a point of flexibility when extra force is exerted. The lighter weight of the product itself also makes it safer when directional force is exhibited.

        In all, although caution should always be exhibited when transporting delicate electronics, we want our consumers to feel safe about their CRYORIG product. Our finely tuned mounting kits are safe to use. Moreover, stationary PC’s do not have anything to worry about either.

Intel Investigates

We reached out to Intel for a comment about the situation. The company stated that it was made aware of the issue only within the last two days. Intel is currently investigating the issue, and a company representative said there “could be several variables at play” but noted that most vendors have relayed that they haven’t had any problems.

Intel did confirm that the substrate design for Skylake processors is indeed thinner than previous designs, but it is rated for the same 50lb. maximum static load as prior generations. The company stated that it doesn’t test third party solutions, but it does provide detailed specifications guidelines for vendors to follow.

Until this situation has been sorted out, it may be a good idea to not travel with your Skylake-based PC unless you remove your heatsink first. If you are looking at building a new PC, stick with coolers that have been confirmed for now.

Intel has now provided an official statement:

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.

Update, 12/4/15, 9:15am PT: Added statement from EK Water Blocks.

Update 2, 12/4/15, 12:20pm PT: Added official statement from Intel.

Update 3, 12/7/15, 10:30am PT: Added official statement from Corsair

Update 4, 12/8/15, 8:25am PT: Added official statement provided by Cryorig

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    Your comment
  • BulkZerker
    $400 CPUs... And Intel is too cheap to brace the heat spreader with $.05 worth of aluminum
  • kcarbotte
    367869 said:
    $400 CPUs... And Intel is too cheap to brace the heat spreader with $.05 worth of aluminum

    its not the heatspreader that is bending, its the substrate that is affected.
    It's also not Intel's responsibility if a company doesn't adhere to Intel's specifications when designing its mounting mechanisms.

    Thus far it seems to be isolated to Scythe coolers but Intel is doing its due diligence to varify that.
  • jimmysmitty
    367869 said:
    $400 CPUs... And Intel is too cheap to brace the heat spreader with $.05 worth of aluminum

    It looks like the issue is one of two cases:

    1. The system is moved around heavily and dropped (such as in shipping) or

    2. The heatsink mounting causes more pressure to be put on than the CPU can handle. This is not due to there not being enough aluminum but rather than the CPU itself is smaller and thinner due to newer technologies.

    This issue probably will not affect 99% of the people.