NVME SM953 Successful Heatsink Installation (Hint: Standard NVME Heatsinks Don't Work)

When receiving my SM953 NVME, I tried running them without heatsinks. While temps were between 32C and 40C most times, under reasonably heavy loads the temps increased enough to set off unRAID temp alerts.

The NVME’s are running as unassigned devices in unRAID. Unassigned devices use general disk settings. These temperature thresholds are located in “Settings - Disk Settings”.

UnRAID uses two temperature thresholds to alert the end user. Here are my settings:

  Default warning disk temperature threshold (C):     45
  Default critical disk temperature threshold (C):    55

I received both alerts at times. And while these general settings can be changed to stop the alerts received for this NVME drive, changing them would also impact the threshold for my other unassigned devices. I didn’t want to do that. Instead, I needed to dissipate the heat to prevent the alerts but more importantly to protect the NVME drives.

When my 110mm NVME heatsinks arrived, I shut down the server and pulled out my SM953 drives only to discover that the standard NVME heatsinks would not work. On the SM953, the capacitors are much higher profile than the controller, so typical NVME heatsinks will not contact the controller on the SM953. I hadn’t realized this prior to ordering the drives and heatsinks; this was my first NVME.

I searched around on Amazon and found various heatsink options. I chose and recommend installing a Raspberry Pi aluminum heatsink to the NVME controller with pre-applied 3M 8810 Thermal Adhesive Tape. From my reading, the 3M 8810 Thermal Adhesive is superior to generic adhesive tapes. And heatsinks pre-installed with 3M tape are fairly inexpensive and easy to apply.

I bought the 40pc pack for $10.99, but the 20pc pack is only $7.99. Having extras is not a big deal, because these can be applied to all kinds of different chips on motherboards and HBA cards when the need arises. Additionally, there are options to purchase fewer heatsinks, but the pricing is near enough the $7.99 that getting this pack is worthwhile.

The first step is cleaning the controller. For this I used rubbing alcohol, a cotton swab and a good quality microfiber cloth. The alcohol and swab cleans the controller; the microfiber cloth dries it.

Next, after being sure the controller is clean and dry, I simply pealed the film from the 3M backed heatsink and applied it squarely to the controller.

Here’s another view:

Yet, another view:

And, finally the two SM953 NVME drives installed in my server.

Conclusion:

Standard NVME heatsinks do not work on SM953 NVME drives because the controller is below the plane of the capacitors.

While under reasonably heavy loads, the SM953 saw temperatures exceeding 55C without heatsinks; with Raspberry pi heatsinks installed on the controller and running the SM953 with continuous writes for a solid hour, temperatures never exceeded 42C.

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