A friend of mine is starting a new build, so we're looking at parts and he wants an M.2 drive, but I could have sworn I heard something about how they're not always the best option to go for. They're more expensive, we know that.

So is price the only reason you wouldn't go for a M.2 drive on a full/mid tower PC?

M.2 drives are the fastest you can go, but SATA SSDs are still pretty fast, so I doubt that the differences in speed would be exceptionally beneficial for gaming and general use. So, unless your friend is planing to take on some heavy workloads like daily video editing/content creation or some other specialized work, or has one of those "fuck it" budgets where he willing to buy all the things, I say sleep on it.

Without digging up the benchmarks and analyzing them in detail (I'm not going to do that), I recall some DOOM loading benchmarks on pre-Skylake hardware showed that a good SATA SSD wasn't far behind a RAM drive, with the M.2 NVMe drives sandwiched in between.

I can't rule out the possibility that post-Skylake hardware shakes that up a bit. They doubled DMI throughput (the DMI link is what allows your storage and input devices to communicate with the CPU) starting with the Z170 chipset, which I think theoretically allows IO from a fast NVMe drive to beat DDR3 (which is what the pre-Skylake chipsets supported) in throughput terms. So I'd need to see new benchmarks. But there are two bottlenecks I can imagine:

• Optimizing for NVMe requires a lot of work, and game developers don't seem to bother with it. Unoptimized you're probably getting a quarter of the advertised peak throughput of the device on average.
• Storage IO may not even be the main bottleneck once you have a reasonably fast SSD anyway. There's plenty of other stuff a game engine has to do to get stored assets ready for use.

That said, it's worth noting that we're in a NAND flash shortage right now, which means every SSD is expensive these days. Last I checked the more reasonable NVMe ones (e.g. the MyDigitalSSD BPX) weren't much more expensive than the SATA drives. So I figure it's probably worth getting one of those.

On the other hand, I wouldn't get a 960 Pro. (I have one. It copies files around really quickly and I have some computer sciency things I plan on using it for, but otherwise it's probably the most irresponsible tech purchase I've ever made, and I only really leapt on it because it was the first of a generation of NVMe drives to hit the market and I didn't have time to wait for the rest.)

Amazon seems to be offering the 960 Pro at a significant discount at the moment ($300 US which is around what I paid for a 950 Pro a year ago). That might be worth going for.

Though it is true that vs. a typical SSD, the practical value of the speed increase is actually not that significant for typical use-cases.

@fnrslvr: Thanks.

M.2 SSD's are incredible, I've got a Skull Canyon NUC that I built with a 960pro in it and the read/write speeds are in the gigabytes per second. The whole thing can reboot in less than 10 seconds provided you install the OS correctly.

I have never understood what m.2 is. It is not a Type of connector as I understand it. As I understand it both pcie and SATA can have m.2? I just plug the SSD into a sata port like I have done with hard drives since sata took over from IDE. I have a mini ITX motherboard so there no pcie slot except for the video card anyway.

A m.2 drive is not faster than a sata drive. They're good for space saving. As for nvme they are faster only for specialized workloads. If you're editing videos and are constantly transferring data back and forth then a nvme is ideal. For 99% of other tasks, including gaming, they are not faster than a sata drive. A sata SSD is still plenty fast.

@dagas: M.2 is the connector. The rest gets confusing, I'd suggest maybe looking at the picture on this Wikipedia page to make sense of the rest of it, because any explanation I give is likely to mutilate the taxonomy of standards they have going on.

I can at least tell you that this thread is about drives which communicate in NVMe over a PCIe hardware bus, typically with the drive plugged in via an M.2 port. (But also there are often variants of the same NVMe drives which can plug into a PCIe slot. See for example Plextor's M8Pe, which has both M.2 and PCIe slot versions.)

On the subject of the M8Pe, that drive has been on sale for little more than the MyDigitalSSD BPX of late, and should be a better drive, so maybe shop around for prices on that? You should probably make sure it's one of the models with the black/red heatsink sleeve, though, because that apparently makes a difference in performance that shows up in benchmarks. (i.e. not just a green board.)