While all Steam Deck 256GB and 512GB models initially came with a PCI express 3.0 x4 SSD, some now ship with a PCI express 3.0 x2 SSD instead.
Using Wayback Machine confirms Valve quietly tweaked the technical specifications listed on the Steam Deck site to reflect these changes in late May, as first reported by Hardware Luxx (via PC Gamer).
Steam Deck Launch Trailer
While Valve claims its testing didn’t find any impact on gaming performance when using the x2 SSD, it didn’t mention any impact on load times or responsiveness.
The storage section of the Steam Deck technical specifications table currently reads:
64 GB eMMC (PCIe Gen 2 x1)
256 GB NVMe SSD (PCIe Gen 3 x4 or PCIe Gen 3 x2*)
512 GB high-speed NVMe SSD (PCIe Gen 3 x4 or PCIe Gen 3 x2*)
All models use socketed 2230 m.2 modules (not intended for end-user replacement)
All models include high-speed microSD card slot
*Some 256GB and 512GB models ship with a PCIe Gen 3 x2 SSD. In our testing, we did not see any impact to gaming performance between x2 and x4.
It said on Monday that it’s planning to significantly ramp up Steam Deck shipments starting this week.
“Production has picked up, and after today we’ll be shipping more than double the number of Steam Decks every week!”