Steam Deck SSD Upgrade Guide – Building a 1TB Steam Deck

SSD benchmarking on Valve’s Steam Deck

To benchmark the performance of our Steam Deck’s SSD, we loaded Valve’s Steam Deck into desktop mode and used the discover tab to download a benchmarking tool called KDiskMark. KDiskMark is a storage benchmarking utility for Linux that works in a similar way to CrystalDiskMark on Windows. 

Simply download KDiskMark using the Steam Deck’s discovery tab, run the tool and start benchmarking. If anything, this install is easier than installing CrystalDiskMark on Windows. 

Stock 64GB Drive (eMMC)

Our Steam Deck is Valve’s £349 64GB model, which uses a 64GB eMMC drive that is too small to hold most modern AAA games and is much slower than Valve’s the 256GB and 512GB M.2 SSD based models. 

With peak sequential read speeds of just over 300 MB/s, it is clear that Valve’s Steam Deck could benefit greatly from faster storage. Not only can an M.2 SSD offer Steam Deck users more storage capacity, but it can also deliver a huge increase in storage performance, making game loading times much faster.

Western Digital’s SN740 1TB 2230 SSD

Using the 1TB Western Digital SN740 that we purchased though Scan, it is clear that our PCIe 4.0 SSD’s performance is limited by the fact that Valve’s Steam Deck is a PCIe 3.0 device. With sequential read speeds maxing out at around 3.5 GB/s, it is clear that our SSD is running at PCIe 3.0 x4 speeds, which is much lower than the 5150 MB/s sequential reads that this SSD is rated for under PCIe 4.0. 

The good news here is that this SSD can saturate the Steam Deck’s PCIe 3.0 interface, which means that this SSD can maximise the Steam Deck’s storage speed potential. With 1TB of storage, this SSD can also store loads of games, making a mockery of Valve’s 512GB Steam Deck model. 

With a £349 Steam Deck and a £110 1TB SSD, we have managed to build a 1TB Steam Deck for £460, which is the same price as Valve’s 256GB Steam Deck. 4x as much storage for the same price as Valve’s 256GB model, and all it took was a little tinkering. Better still, this SSD is faster than the SSDs used within Valve’s 256GB and 512GB Steam Decks.  

You can join the discussion on our Steam Deck SSD upgrade guide on the OC3D Forums.