Valve has made changes to the SSDs built into the Steam Deck without much notice and theoretically halved the bandwidth – but this has no effect on performance in games, as the manufacturer has now appeased. However, Valve does not reveal which model numbers are affected.
Four lanes secretly become two or four
Apparently since May 28, 2022, Valve has been listing modified technical details on the English-language website for the Steam Deck: In the two variants with 256 GB and 512 GB NVMe SSD, the connection is no longer necessarily via PCIe Gen 3 × 4, but potentially also only over 2 lanes, as user “kaiser” first noticed in the Hardwareluxx forum. Valve has not yet communicated the changes on the German-language website, nor has there been a corresponding press release or the like on the subject.
The smallest and cheapest Steam Deck variant, on the other hand, only has a 64 GB eMMC memory card, which is connected via a single PCIe Gen 2 lane. The version of the PCIe interface and the number of lines used determine the maximum possible data rate, which does not necessarily have to be exhausted by the connected device. Graphics cards, for example, are usually connected to the CPU via 16 PCIe lanes of generation 3 or generation 4, which is now becoming more common; PCIe 3.0 and PCIe 4.0 with 4 lanes are common for NVMe SSDs in the M.2 form factor.
- 64 GB eMMC (PCIe Gen 2 ×1)
- 256 GB NVMe SSD (PCIe Gen 3 ×4 or PCIe Gen 3 ×2*)
- 512 GB high-speed NVMe SSD (PCIe Gen 3 ×4 or PCIe Gen 3 ×2*)
*Some 256GB and 512GB models ship with a PCIe Gen 3 ×2 SSD. In our testing, we did not see any impact to gaming performance between ×2 and ×4.
The updated Steam Deck technical details
As PCGamer notes, older 512GB versions of the Steam Deck come with a Phison ESMP512GKB4C3-E13TS SSD. This is an M.2 2230 SSD specially produced for the Steam Deck – the number in the middle indicates the physical size of the plug-in card. According to the identifier, a variant of the Phison controller E13T with PCIe 3.0 x4 is used. The chip is also available in variants with PCIe 3.0 x2, one of which could be in the new version. An SSD with Phison E8T or a completely different controller would also be conceivable. Only the identification of the new SSDs will provide clarity here.
There should be no difference for gaming
Even with PCIe 3.0 x2, the SSD should still be significantly faster than SSDs with a SATA interface. According to Valve, this is enough to achieve performance equivalent to games, as the manufacturer explains when asked by PCGamer. There are only differences in “extremely unusual scenarios”.
Our team has tested both components extensively, and determined that there is no impact to performance between the two models. SSD performance is currently gated by factors not related to PCIe bandwidth. In extremely uncommon cases, differences in read/write speed caps may minimally impact file transfer speeds, but OS performance, loading times, game performance, and game responsiveness are identical between the x2 and x4 drives.
Many Steam Deck components come from multiple suppliers for improved redundancy and production capacity. One of our SSD suppliers provides PCIe Gen 3 x4 NVMe SSDs, while another provides a x2 SSD.
Lawrence Yang, Valve
Valve cites positive effects on supply chain redundancy and production capacity as the reason for the potential adjustment – the different SSDs would come from different suppliers. In view of the current circumstances with chip shortages, cross-industry delivery problems and lockdowns in China, it is quite conceivable that the production of the Steam Deck could only be doubled in this way. Apart from an insufficient offer, price increases for the corresponding ×4 controllers or SSDs are also conceivable.
Valve does not specify from which serial number Steam Decks can have the slower SSD or from which point in time the corresponding devices were delivered. Interested users can learn more about their own Steam Deck by searching for “Device Viewer” in Desktop Mode, then selecting “Storage Drives” and then tapping “Hard Disk Drive”.
Longer SSDs are not a solution
Just a few days ago, the Steam Deck in the context of its SSD slot was the focus of reporting. In addition to M.2 2230 SSDs, slightly longer plug-in cards with the M.2 2242 form factor can also be installed; However, Valve strongly advises against it: the heat development is higher and reduces durability.