Are NVMe PCI-E 3.0 x4 and NVMe PCI-E 4.0 x4 the same physical size?


The Contraceptive Under the Sea
Jan 15, 2011
Are these M.2 drives 3.0 and 4.0 the same physical size? I've never really looked at them in person but looking at some B550 mobos it looks like the 4.0 could be bigger? It might just be my imagination though since some come with heatsinks and some don't.
If it says M.2 2280, it means a M.2 connector on one end, with overall card dimensions of 22mm by 80mm.

Other common sizes are 2230 (often used in WiFi cards, but MSFT also uses them for SSDs in Surface and Xbox Series as do some laptop OEMs), 3042 is used a lot for LTE/5G cards, though 2242 cards also work in 3042 mounting points. 2242 being a somewhat common OEM size for SSDs, though not overwhelmingly common. 2280 is quite common. 22110 is also somewhat out there.
Should be the same size. Afaik, PCIe 3.0 and 4.0 are electrically the same. M.2 slots shouldn't have changed either.
In ~general~, you have a pile of 80mm or 110mm slots on the board. Smaller ones for a WIFI card (it is, after all, a glorified mini-PCIE slot). Almost all SSDs are 80mm.
They will be the same in the x and y axis (length and width), but some of the higher performance PCIe 4 models come with thicker heat sinks which will increase their size in the z axis (height).
Feeling lazy to do google search but I think they have the same overall footprint but physically the 4.0x4 has greater physical electrical conductor size or contacts. It must be designed to physically elctrically conduct better and this is why to get best conduction you have to have a motherboard that is capable of physically matching the physical rated size/design to get the full rated speed and the processor also has to have the physical contact areas and processing control to make it all happen.

my theory.

It's hard to find drawing for this stuff. I don't think it is marketing though. I think it is more about physical design.