Why on Earth is M.2 the dominant NVMe SSD interface?
Chris Szewczyk explains why M.2 SSDs need to go the way of the Dodo.
It came to a climax when benchmarking X570 motherboards. M.2 SSDs are just horrible. There I was, removing tiny screws, pulling off a heatsink half the size of the motherboard, dropping said tiny screws just a little too often, all to connect one SSD. Surely there has to be a better way? And there is! It’s called U.2.
Let me just state that there’s nothing wrong with the M.2 interface itself. It’s perfectly suited for a lot of devices. Wi-Fi? Bluetooth? Those kinds of devices are compact, use little power and are perfect for adding functionality in constrained spaces where a PCIe add-in card isn’t feasible. The problem is that the M.2 form factor, specifically the 2280 sized one that’s easily the most prevalent, just isn’t suited to huge throughput, high end enthusiast SSDs.
Modern NVMe drives run hot. So hot that they can and do throttle to protect themselves. Do you really want your critical data subjected to that? Consider that modern enthusiast systems equipped with AIO water cooling lack airflow across the board. Then there’s the positioning of many M.2 slots directly adjacent to a hot GPU. It’s not exactly conducive to having a cool running, long life SSD. This will only be exacerbated by PCIe 4.0 drives. The Aorus PCIe 4.0 drive we used for testing with X570 has a hefty, all enclosing copper heat sink. Why equip it with that if it doesn’t need it?
Witness the lengths drive and motherboard manufacturers are going to keep SSDs cool. Either drives are coming with pre-attached heatsinks or motherboard makers are resorting to covering half the board with a gigantic cooling apparatus. As we see with X570 motherboards elsewhere in this issue, chipset fans have made a return. Depending on the board, they aren’t
necessarily just there to keep the chipset cool, they’re there to keep hot NVMe drives cool too.
A few years ago, high end boards came with a U.2 connector but now sadly, it’s relegated almost exclusively to the professional market. Essentially it offers the same functionality as M.2, but connects via a cable instead.
U.2 drives have so many advantages. You can keep them isolated from other hot components, cool them easier and prevent them from throttling, leading to a longer life and hence keep your data safer. Manufacturers won’t be constrained by the 80mm wide PCB and therefore offer larger capacities, improved heat dissipation properties and free up motherboard real estate. A 2.5-inch U.2 drive can be inserted into any case that has 2.5-inch support (as in, all of them).
For some reason, somebody (who?) decided that attaching an SSD directly to the motherboard was a good idea. Is it the aversion to having a visible inch of cable coming from a port? Are aesthetics so important that they outweigh every other concern? Why not just make an RGB U.2 cable? Problem solved!
So, big Multinational Corporation, can I have U.2 drives please? They won’t throttle, they’re cooler and more convenient. I can stash them out of sight and I’d feel safer about my data’s integrity. Please? Pretty please?
“Chipset fans have made a return. Depending on the board, they aren’t necessarily just there to keep the chipset cool, they’re there to keep hot NVMe drives cool too. ”