Quick Answer
For 4K video editing in SA, M.2 NVMe is the right choice over U.2 for most editors — a fast Gen4 drive scrubs 4K timelines smoothly and fits cleanly, costing less than U.2. Use two M.2 drives: one for the OS/apps and a 2TB scratch drive (around R2,400) for active 4K projects. U.2 only suits large studio servers.
Why editors want fast NVMe
4K editing reads and writes huge files — a single minute of 4K footage can be gigabytes. A Gen4 M.2 drive at around 7,000 MB/s keeps timeline scrubbing and exports responsive. M.2 and U.2 share NVMe speed, but M.2 fits a creator desktop cleanly and costs less, so it is the practical pick. A two-drive setup keeps the OS separate from project files.
A sensible editing storage layout
Run your OS and apps on one M.2, edit active projects on a dedicated 2TB M.2 scratch drive, and archive finished work to a larger drive. This keeps reads and writes from fighting each other and keeps 4K playback smooth. U.2 becomes relevant only in studio servers handling many editors at once; for a solo or small creator desktop, M.2 covers every need at lower cost.
How to choose for an SA build
For nearly every desktop and gaming PC sold locally, M.2 is the answer — motherboards from B650 to X670 carry two to four M.2 slots, and drives like the WD Black SN770 1TB (around R1,300) or a 2TB Gen4 unit (around R2,400) cover gaming and creative work. U.2 needs an adapter or a workstation board, adds cost, and gives no real-world speed benefit for home use. Buy U.2 only if you specifically need enterprise drives in a server chassis.
FAQ
Does a fast SSD help 4K editing?
Yes. A Gen4 M.2 drive at around 7,000 MB/s keeps 4K timeline scrubbing and exports smooth versus a slower drive.
How should I lay out storage for editing?
Use one M.2 for OS/apps and a separate 2TB M.2 scratch drive (around R2,400) for active projects, then archive finished work elsewhere.
When is U.2 actually needed?
Only in studio servers serving many editors. For a solo or small-team creator desktop, M.2 covers every need at lower cost.
Before you buy
For 4K editing, run a separate 2TB M.2 scratch drive for active projects so timeline scrubbing stays smooth.