Skip to main content

Valve Halves Steam Deck SSD Bandwidth on Some Models

Steam Deck open
(Image credit: Valve)

According to a report by HardwareLuxx, Valve has made a spec change to the Steam Deck's SSD specs on May 28 that has largely flown under the radar. The change allows the use of two drive configurations instead of just one, cutting the potential SSD bandwidth in half for some models. As a result, the PCIe Gen 3 NVMe drive built into the higher-end models will now come with access to either four PCIe lanes (x4) or two lanes (x2). However, customers won't know which drives they'll receive, with the company noting that, "Some 256GB and 512GB models will ship with a PCIe Gen 3 x2 SSD."

Valve says that it tested the change and it will not affect gaming performance. Here's Valve's description of the change: 

"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*)

*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."

Valve doesn't say why it made the change, but there are still a number of NVMe SSDs on the market that only support two PCIe Gen 3 lanes. In fairness, SSDs of this caliber are still very capable drives, and much faster than SSDs with the SATA 3 interface. With a two-lane SSD running at Gen 3 speeds, you can still receive up to 2048 MB/s of bandwidth, which is four times greater than SATA SSDs. However, that's half the theoretical peak of the x4 connection found in some models. As a reminder, only a handful of games made today can utilize the full storage bandwidth of an SSD. For more details on SSDs, check out our Best SSDs article.

The 256GB and 512GB NVMe models are the only models receiving this change. The baseline 64GB model will stay the same with its much slower eMMC drive running on a PCIe Gen 2 x1 configuration. There is also no option to choose, or know, which type of drive you'll receive — it appears to be a bit of a lottery. We're reaching out to Valve for more detail. 

Valve also confirmed that the spec changes are only for the NVMe drives, while the high-speed MicroSD slot will remain identical between all three variants. The company recently announced that it is doubling its production every week, so you can expect to see a lot more of the devices in the wild soon. 

Aaron Klotz
Aaron Klotz

Aaron Klotz is a freelance writer for Tom’s Hardware US, covering news topics related to computer hardware such as CPUs, and graphics cards.

  • Alvar "Miles" Udell
    Sounds like a way to draw a lawsuit, and to prevent user upgrades...
    Reply
  • Foxlum
    This is just bad form on Valve's part, as it severely kneecaps any chance of improving storage performance on the users part.
    Reply
  • cryoburner
    Considering everything from a low-end SATA SSD to a high-end PCIe 4.0 NVMe SSD offer very similar performance at loading today's games (and most other desktop tasks) this isn't likely to matter much.

    Alvar Miles Udell said:
    Sounds like a way to draw a lawsuit, and to prevent user upgrades...
    Foxlum said:
    This is just bad form on Valve's part, as it severely kneecaps any chance of improving storage performance on the users part.
    They're just using a different drive that has an x2 interface. That shouldn't affect potential upgrades in any way, and it doesn't sound like the x4 interface supported by the system will be changing, just the drive.
    Reply
  • anonymousdude
    Alvar Miles Udell said:
    Sounds like a way to draw a lawsuit, and to prevent user upgrades...

    It sounds like they're just changing the drive it ships with. Not the actual physical link. Lawsuit maybe. Winnable lawsuit, probably not. They did straight up tell you that they're changing it. It honestly sounds like a supply chain issue for me and this is what they could source. They did announce that they doubled Steam Deck production per week so I wouldn't be surprised at all if this was the compromise.

    Foxlum said:
    This is just bad form on Valve's part, as it severely kneecaps any chance of improving storage performance on the users part.

    Not too sure your average user or ever power user would particularly care or notice. Gaming as of right now doesn't hit storage all that hard and if you're on an ssd game load times aren't meaningfully different. The important part is that you're on an SSD.
    Reply
  • garlicky
    Alvar Miles Udell said:
    Sounds like a way to draw a lawsuit, and to prevent user upgrades...
    Exactly what damages would you claim for the lawsuit?
    Reply
  • Old Molases
    But why on earth would they do thiss??
    Reply
  • digitalgriffin
    Admin said:
    Valve has made a new change to the Steam Deck's original specifications, and is now allowing either a two-lane or four-lane NVMe SSD, which will reduce storage bandwidth on some models.

    Valve Halves Steam Deck SSD Bandwidth on Some Models as Production Doubles : Read more

    Was that testing on the x2 / x4 lanes done on a mostly full drive or < 1/2 full drive? SLC cache is a thing that shrinks with available space left.
    Reply
  • cknobman
    Alvar Miles Udell said:
    Sounds like a way to draw a lawsuit, and to prevent user upgrades...

    How does this prevent you from doing user upgrades?
    Reply
  • junglist724
    digitalgriffin said:
    Was that testing on the x2 / x4 lanes done on a mostly full drive or < 1/2 full drive? SLC cache is a thing that shrinks with available space left.

    Not really important when the CPU is a low power quad core. When I'm installing games on my deck it's basically pinned at 100% cpu usage and never exceeds 90MB/s of disk activity even when docked and on gigabit ethernet. Game loading is CPU bottlenecked too.
    Reply
  • Thunder3000
    SSD speed scales with the number of NAND chips, because the drive can write to (and hopefully read from) all the NAND chips simultaneously. A 4TB SSD usually has 64 chips or less. A 512 GB SSD? Probably 4 or 8. Hard to saturate the bus with that. There are also power considerations to lighting up too many NAND chips at once. Bottom line is that Valve is probably 100% right, it doesn't matter.
    Reply