SSD speeds have continued to skyrocket with PCIe Gen 4 and Gen 5, and with it, so have their thermal demands. M.2 drives may be tiny, but they can run surprisingly hot under load, especially in compact cases or poorly ventilated spots on your motherboard. Without a heatsink, many of these drives will throttle down, lose consistency, or even wear out faster than expected. That’s when an M.2 drive heatsink goes from an optional add-on to something that can make a big difference.

When using drives that support PCIe 4.0 or 5.0

Faster speeds come at a cost

PCIe Gen 3.0 is fast, don't get me wrong, but PCIe 4.0 and 5.0 have upped the ante significantly. When you're increasing speeds by more than 3x, that speed comes at a cost, and unfortunately, that cost is thermals. The controllers on these fast drives can generate a significant amount of heat, especially under sustained workloads. Working with ultra-high resolution video or streaming large texture files during can put a significant load on your drive.

These M.2 drives aren't immune to thermal throttling, and most will begin to do so at around 70 degrees Celcius. Performance will nose-dive as a result, and in order to keep performance in check, an M.2 heatsink becomes imperative. A thermal pad combined with a decently sized heatsink can shave more than 10 degrees off of operating temps, and keep performance at PCIe 4.0 or 5.0 rated speeds.

In a small-form-factor case

Small space means more concentrated heat

When it comes to smaller spaces, the battle against heat is always going to be a struggle. When it comes to the larger components, such as the GPU and CPU, dealing with this heat is usually just a matter of ensuring proper airflow in and out of their respective cooling systems. In an SFF case, this has likely been considered by the designer, so there isn't much to be done there.

When it comes to your M.2 SSD though, dissipating that heat suddenly becomes more challenging, as it's likely buried beneath layers of other components and wiring. Heatsinks pull heat away from the components, and while passive airflow will be relatively limited in a small-form-factor build, an M.2 drive with one will be able to reach its rated speeds for longer than one without one.

Awkward slot placement

Residual heat has to go somewhere

One slightly annoying hardware trend in recent years is the placement of M.2 slots on motherboards. There isn't a lot to be done about this, but unfortunately, the higher speed M.2 slots tend to be closer to the CPU socket, usually just below the first PCIe slot. This is the slot that most users use for their GPU, so you can see where I'm going with this.

Being stuck behind a massive chunk of hot metal and silicon (perhaps the hottest part of your rig) isn't exactly conducive to great thermal performance. The residual heat coming off of your GPU can be absorbed by your SSD, further adding to its thermal load. To make matters worse, it almost certainly limits the height of M.2 heatsink that your drive can comfortably have in that high-speed slot.

Fortunately, all high-end motherboards and most mid-range boards offer some sort of M.2 heatsink for the highest speed slots. This doesn't eliminate the problem entirely, but it certainly helps dissipate that heat created by your drive.

When longevity is a priority

Heat is always enemy number one

Whenever you're thinking about the longevity of any PC part, thermals are always a consideration, no matter how small the component. Excessive heat for long periods of time will decrease the lifespan of even the toughest components, and M.2 SSDs are no exception.

Most of the high-performance drives will come with a heatsink of their own, or they'll have a different SKU of the same drive that has one. Every degree shaved off matters for longevity's sake, even if it might not seem like much. A longer lasting drive means it can live multiple lives; your boot drive, a scratch disk in your main rig, or a storage pool in your NAS.

Thermals are paramount for storage longevity and performance

M.2 SSDs are no exception to that. Heat is no longer just a side effect of these drives, it's become the limiting factor. They aren't always necessary, but a heatsink is a simple addition that can ensure your M.2 drive runs at its full advertised speeds, avoids mid-transfer slowdowns, and lasts longer in the process.