Quick Answer
A Z790 board gives you generous fast storage: typically four M.2 slots, with one PCIe 5.0 x4 slot and the rest PCIe 4.0, plus several SATA ports. That lets a Z790 builder run one Gen5 NVMe boot drive (1TB around R2,200-R2,800) alongside two or three Gen4 drives for games, without sacrificing the GPU's PCIe 5.0 x16 link.
How Z790 Allocates Storage Lanes
On LGA1700, the CPU supplies the GPU's PCIe 5.0 x16 link plus a CPU-connected M.2 slot, while the Z790 chipset feeds the remaining M.2 and SATA ports over its DMI link. The headline layout is one Gen5 M.2 (often CPU-connected), two to three Gen4 M.2 slots, and four-plus SATA ports. That covers a fast OS drive, a large game library and a backup HDD comfortably.
Building A Sensible Storage Stack
Put Windows and your most-played titles on a Gen5 or fast Gen4 NVMe (1TB Gen4 around R1,400-R1,800), use a second 2TB Gen4 drive for the wider library, and add a SATA HDD for bulk storage if needed. Watch for slot-sharing: filling certain M.2 slots can disable SATA ports on some boards, so check the manual's lane-sharing table before populating every slot.
Gen5 Versus Gen4 In Practice
Gen5 drives top 12,000 MB/s on paper, but in real games the load-time gap over a good Gen4 drive is small. Spend on capacity first; a single fast Gen4 drive plus generous space usually beats one small Gen5 drive.
FAQ
How many M.2 slots does Z790 have?
Most Z790 boards offer four M.2 slots, typically one PCIe 5.0 and the rest PCIe 4.0, plus four or more SATA ports for additional drives.
Will adding M.2 drives disable SATA ports?
On some boards, yes. Populating certain M.2 slots shares lanes with SATA ports, so check the board manual's lane-sharing table before filling every slot.
Is a Gen5 SSD worth it on Z790?
For pure gaming the load-time benefit over Gen4 is small. Prioritise capacity and a good Gen4 drive, then add Gen5 only if you move very large files often.
Z790 board manual's lane-sharing table before adding drives; some M.2 slots disable SATA ports when populated.
