Sorting NVMe storage on a Z790 board comes down to a few decisions that matter and several that do not. Here is what a Polokwane builder should actually weigh before buying.
Quick Answer
On a Z790 board, a single fast Gen 4 or Gen 5 NVMe beats a RAID 0 pair for gaming: real-world load times barely change, and RAID 0 doubles your failure risk with no TRIM passthrough on many setups. Buy one larger, faster drive instead of striping two smaller ones. Reserve RAID 0 for specific scratch-disk workflows, not your game library.
Where RAID 0 helps and where it hurts
RAID 0 stripes data across two drives for higher sequential numbers, but game load times depend on random access and queue depth, which barely improve. Meanwhile you double the chance of total data loss and often lose TRIM passthrough. A single 2TB Gen 4 or Gen 5 NVMe gives you the capacity and speed without the fragility, and it is simpler to back up.
Pairing it with your Z790 board
Use the CPU-direct primary M.2 slot for your fastest drive so it gets full lanes, and mount it under the supplied heatsink. Polokwane climates run warm, so confirm one case fan pulls air across the M.2 area. For most SA gamers a single 1-2TB Gen 4 drive is the right call: it is simpler, cooler and easier to back up than juggling several smaller drives. Update the board to the latest stable BIOS for the best NVMe compatibility before you install Windows.
SA pricing and what to actually buy
At local retail a solid 1TB Gen 4 TLC drive sits around R1,100-R1,600, a 2TB around R2,000-R3,000, and a 2TB Gen 5 with heatsink in the R3,500-R5,000 band. For a gaming-first Z790 build, a 2TB Gen 4 TLC drive with DRAM is the value sweet spot; Gen 5 is worth it mainly if you move very large files often. Buy the capacity you need now plus headroom, because adding a second drive later is cheap and easy on this platform.
FAQ
Do I need a Gen 5 NVMe for gaming on a Z790 board?
Not really. Game load times are nearly identical between a fast Gen 4 and a Gen 5 drive because games rarely saturate the bus. Gen 5 (around 7,000MB/s) only pays off for very large file transfers or editing scratch work.
How big should the drive be?
For a gaming-first build, 2TB is the comfortable size today, leaving room for a few large titles plus Windows and software. A 2TB Gen 4 TLC drive runs about R2,000-R3,000 at SA retail.
Will heat damage the drive in SA's climate?
Only if it runs uncooled. Mount the NVMe under the board's bundled heatsink and keep one case fan moving air across it; that holds the controller under 65C and stops thermal throttling even in a hot Polokwane room.
drive to the slot: put your fastest NVMe in the CPU-direct primary M.2 socket under the supplied heatsink, then confirm one case fan moves air across it. That single step at build time prevents thermal throttling in a warm Polokwane room.
