[throwaway8941]

And the much higher temperatures (if your M.2 is an NVMe). Could anyone knowledgeable explain why NVMe tend to get much hotter than SATA under similar conditions? I've been testing mine with not more than 400-500 MB/s and it quickly gets to 60°C+, while the old 840 Evo doesn't get above ~45°C (running a very similar synthetic workload). I would've guessed the opposite: the fully enclosed SATA drive should get much hotter.

[Ygg2]

I'm not sure if I count, but I suspect two things. Heat dissipation and controller complexity. NVMe controller might be more computationally heavy and so they might emit more heat*.

But assuming that NVMe and SATA SSD controllers emit the same energy, it makes more sense that NVMe would be hotter.

Think about it. If you throw a ball of high heat meat would it cool faster if it was connected to a large body of water (SSD with its chasis) or a small body of water (NVMe small piece of plastic that is the NVMe)?

Another thing to check if your NVMe either has proper thermal pads placement and/or if the air from the front coolers is reaching it.

[kasabali]

> NVMe controller might be more computationally heavy

Which is ironic because NVMe was supposed to be more efficient and doing less work because it's design wasn't bound with SATA&spinning assumptions and controller doesn't need to handle pcie-SATA conversions since it's directly connected to the bus etc.

[magicalhippo]

Well a 2.5" drive has a much larger surface area from which the heat can dissipate.

There's also the location of the temperature probe, it doesn't need to be much further away from the heat source to register drastically lower temperatures in either case.

[_jal]

Not sure about yours, but on my motherboard, it floats - other than the connector on one end and the screw on the other, there is no heat sink, and it just doesn't mass very much.

[jeffbee]

m.2 cards can sink a pretty surprising amount of heat through the connector and the standoff. But case makers can also provision for cooling m.2 cards. Components on m.2 modules are permitted to be 1.2-1.5mm high. My Intel NUC cools the m.2 device through a flexible thermal interface to the system's main cooler (that also cools the CPU). This works extremely well.

One problem with m.2 is the spec would permit a module with the controller on the bottom where it would be difficult to cool. But I think so far nobody has been dumb enough to ship one.

[jeffbee]

Why do you care? The critical temperature on a retail 970 Pro is, IIRC, 84C, and is almost impossible to hit.

[throwaway8941]

Mostly out of curiosity. Higher temperatures also put additional stress on flash memory, and I tend to run my hardware into the ground (I'm still using a 50GB Intel SSD from 2010), so there's that.

[pixl97]

Fully enclosed SATA has a much larger surface area to radiate heat.