Do I need a heatsink for 970 evo plus to use in 27" late 2015 iMac?

M.2 blade SSD makers over hype the heatsink!

Think of it this way you have a water tap which is pumping out one quart of water per minute. Now you have a one gallon container just below so within four minutes the container is full! So clearly it can’t hold more.

Now let’s look at how a CPU heat sink works. Using the exact same model, now lets add a hole at the bottom of the gallon container which allows 1/5th of a gallon, so it allows some of the water to exit but not at the same rate as what was filling the container so a full rate will still overflow the gallon container. Luckily, CPU’s don’t always push things to the max all of the time.

So with this model let’s look at the blade SSD heat sink. Here it’s of little use as it doesn’t have an effective means to shed the heat it builds up. So as soon as it is loaded it offers no benefit! While there is some heat shedding to the air directly its not effective enough when running the SSD hard.

To add to this the means of attaching the heatsink is in its self gets in the way too! Just like a CPU heat sink the least amount of material between the two Metal surfaces (or Chip/Metal in a laptop) is important! Thats why we use thermal paste which fills the microscopic surface imperfections to improve thermal transmission.

To be clear an active heatsink system makes a big difference. A passive design like this is of little use.