What you're actually paying for
Three hundred and forty quid for an SSD is a commitment. The SN850P is officially licensed by Sony, which matters more than it sounds - it means WD has validated compatibility with PS5's thermal and firmware requirements, so you're not gambling on whether it'll play nicely with the console. Read speeds hit 7300 MB/s, which is comfortably above the PS5's internal drive. In practice you won't notice load time differences at that level, but you won't be leaving performance on the table either.
Who actually justifies this purchase
The honest case for 4TB: if you own a lot of large modern titles (Call of Duty alone can eat 150GB), the base PS5 storage becomes a revolving door of installs and deletions. At 4TB you're looking at storing 20 to 30 full-size games simultaneously. For someone who buys rather than subscribes, that has real value over time. Amortised over three or four years of heavy use, the premium over a 2TB option is maybe £3 a month. That's fine.
If you play two or three games at a time and don't mind managing storage, the 2TB version at roughly half the price is the sensible call. This 4TB isn't for casual players.
The honest weaknesses
The broader M.2 SSD segment has one persistent annoyance: heat. Fast NVMe drives run warm, and while the PS5's expansion slot has some airflow, a heatsink is strongly recommended. The drive doesn't include one, which at this price is a mild irritation. Budget another £10 to £15 for that.
Also worth noting: 7300 MB/s sequential reads look impressive on paper, but real-world gaming load times are largely bottlenecked elsewhere. You're paying for capacity and peace of mind as much as raw speed.
