Valve recently updated the specs for the Steam Deck, noting that models could ship with either a PCIe Gen 3 x4 or PCIe Gen 3 x2 variant of the 256 GB and 512 GB NVMe SSDs.
This change was first noticed by German hardware site HardwareLuxx. The “x4 or x2” refers to the number of PCI lanes the SSD has access to. More lanes equals more bandwidth. So the change means that some units of the Steam Deck have half the bandwidth as compared to others. There is also no way of knowing what kind of unit you will receive upon ordering a new device, at least as of this writing.
However, in a footnote on the official specs page, Valve states that “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.” According to Tom’s Hardware, two-lane SSDs can receive 2048 MB of bandwidth, which is four times what SATA SSDs can.
It does seem that for most gaming experiences, performance is unlikely to be affected by this change due to the fact that so few PC games are designed to take advantage of NVMe SSD speeds. Steam Deck designer Lawrence Yang also told PC Gamer that the change assists Valve in making and shipping more units of the in-demand device. Valve also recently announced it is ramping up production on the Steam Deck.
The 64 GB Steam Deck model remain unchanged; it has a 64 GB eMMC (PCIe Gen 2 x1). The microSD card slots are also standard across all three models. Valve also recently recommended against modding the Deck to put in a larger SSD.
Source: Gamespot
