Written Article:
https://www.eurogamer.net/articles/...e-storage-tested-can-it-match-the-stock-drive
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Our final tests were all about raw transfer speeds, where moving games between PS5's stock drive and the M.2 expansion is a perfect case study. Picking Cyberpunk 2077 gives us a meaty 101GB install to shuttle between these two drives. After extensive testing, it became clear that writing to the M.2 drive happens at a much more rapid pace than copying the same data back to the internal drive. For example, transferring Cyberpunk from PS5's internal SSD to the M.2 SSD takes just one minute and 11 seconds. That's an average rate of 1.42GB/s - an incredible speed given the sheer size of CDPR's game. Transfer speeds do vary according to content though, and so for example, copying Battlefield 5 from internal storage yielded a 0.87GB/s average transfer speed, while Final Fantasy 15 produced a 0.82GB/s average.
But if we transfer the game back, from the M.2 SSD to the PS5 stock drive, it takes far longer. The count comes in at seven minutes, 18 seconds - at a transfer rate of just 0.23GB/s. It's a huge difference, and one that bears out in transferring other big games - like Final Fantasy 15 and Battlefield 5. Transferring to the M.2 SSD will always be faster than it will be writing back to the internal drive, but generally speaking that is fine: a console SSD does not need tremendous write speeds. It's worth noting that while very slow, it's actually relatively fast when stacked up against copying back to the internal SSD via a USB-based option, as the table below reveals. Copying Battlefield 5 and FF15 back to internal storage delivered the same 0.23GB/s transfer rate average, suggesting some kind of system level cap.
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So, that's our first look at PS5 expandable NVMe storage for the M2 slot, but it's unlikely to be our last - we're interested in testing the best of the best and indeed the worst of the worst, not to mention the WD SN850 selected by Mark Cerny himself,
based on this recent tweet which does seem to hit the sweet spot in terms of hardware specs, and comes with a heatsink attached out of the box. And if there are any other specific drives you'd like us to test - please let us know - but in the here and now, the news is good: PS5 may well be built around a custom solid-state storage solution, but a good PCIe Gen 4 SSD can match and in some scenarios actually exceed the performance of the internal solution, and works just as well on the most demanding storage-heavy game we've currently got to test.