Thermal Throttling

Due to the compact form factor, M.2 drives lack the ability to actively cool themselves, usually having to rely on passive airflow instead. All vendors include some form of thermal throttling on their drives as a safeguard, which limits throughput once a certain temperature is exceeded.

On this page, we will investigate whether the tested drive has such a mechanism, how high temperatures get, and what effect this has on performance. We will test the drive in a typical case, installed in the M.2 slot between the CPU and VGA card, while it's getting hammered by non-stop incoming writes. A first test run, to create a baseline, shows temperature and performance with a 120 mm fan directly blowing on the tested drive. In a second run we report thermal performance of the completely uncooled drive. Each of the charts has time moving from left to right, with the blue line displaying transfer speed in MB/s and the red line showing the temperature in degrees Celsius (measured using SMART).

Results from this test setup are not comparable to our older SSD benches because we're using a different case and an AIO watercooling unit, so there's very little airflow inside the case.

Bare Drive with Heat Spreader

In this scenario, the drive will throttle after only a few seconds—no way to run this reliably.

Drive with Fan blowing on Heat Spreader

Even with an 80 mm fan that's blowing right on the heat spreader there's A LOT of thermal throttling.

Drive with Thermalright Heatsink

With a Thermalright TR-M2, which is a compact full-metal heatsink things are better, but still, some throttling.

Drive with big Thermalright Heatsink

With the much bigger Thermalright HR-10, there is almost no more throttling.

Thermal Image & Hot Spot

We recorded a thermal image of the running SSD as it was completing the write test. Even with a decent Thermalright heatsink the surface temperature of the drive reached 92°C, which means the controller is even hotter.