Quick Answer

Before ordering a Gen4 NVMe SSD, confirm your motherboard has a PCIe 4.0 M.2 slot, or the drive (around R1,200-R1,800 for 1TB, reading 5,000-7,000 MB/s) will run at Gen3 speed. Check the M.2 form factor (almost always 2280), whether the slot shares lanes with SATA ports, and that a heatsink is available so the fast drive does not thermal-throttle.

Slot, generation and form factor

A Gen4 drive only reaches its 5,000-7,000 MB/s in a PCIe 4.0 M.2 slot; in a Gen3 slot it caps near 3,500 MB/s. Most current B650, X670, B760 and Z790 boards have at least one Gen4 slot, often a Gen5 slot too. Confirm the slot length supports the standard 2280 form factor, which nearly all consumer drives use. Some boards disable a SATA port or share lanes when a second M.2 is populated, so read the manual to avoid losing a drive connection you need.

Heat and the rest of the checklist

Gen4 drives run warm under sustained writes, so use the motherboard's M.2 heatsink or buy a drive with one built in, or the controller throttles and speed drops. Confirm your CPU and board generation support PCIe 4.0; very old systems may only offer Gen3. Size to 1TB for the OS and games or 2TB for a larger library, and keep 15 percent free for sustained speed. For gaming the felt gain over Gen3 is modest, so the main reason to choose Gen4 is fast large-file work or future-proofing on a modern board.

FAQ

Will a Gen4 NVMe work in a Gen3 motherboard?

Yes, but it runs at Gen3 speed, about 3,500 MB/s, not its full 5,000-7,000 MB/s. For full speed you need a PCIe 4.0 M.2 slot, so check your board before paying the Gen4 premium.

Do Gen4 NVMe SSDs need a heatsink?

Under sustained writes, yes, or they thermal-throttle and slow down. Use the motherboard's M.2 heatsink or buy a drive with one built in to keep the Gen4 speed steady.

Does adding an M.2 drive disable other ports?

On some boards, yes. A second M.2 slot can share lanes with a SATA port or the GPU slot, disabling one when populated. Check the motherboard manual to avoid losing a connection you rely on.

Confirm a PCIe 4.0 M.2 slot and a heatsink before ordering a Gen4 NVMe, check whether the slot shares SATA lanes, and size to 1TB or 2TB with 15 percent kept free.