It’s complicated. The internal SSD is noticeably faster in games that load a lot of assets. AAA titles, or games with more complex environments, will load much more slowly on an SD card.

Where this discussion gets more fun is comparing the more expensive A1 to A2 MicroSD cards. A2 is generally the default recommendation for Steam Deck users. But this isn’t as drastic as the difference between the internal and external expansion options.

I have an OLED arriving today; after testing extensively on my prior Deck and Ally, my recommendation is always to prefer upgrading the internal SSD first, which is more expensive, then pick up a MicroSD card that meets your needs for capacity, not speed, and save your money on that purchase instead.

In my case, I picked up the Sabrant 2tb SSD for my OLED, which is probably the best drive you can purchase for the device, but I went with the SanDisk A1 1.5tb drive for my MicroSD card. It’s pricy only because of the capacity — it was more important for me to have additional space for my roms/emulators than it was to have speed. But a simply 512gb or 1tb A1 card will probably work for most people.

I’ll be loading all of my Steam games from the internal drive, and all of my roms (and likely some indie titles) from the MicroSD. This setup worked well on my original Deck and Ally, and I never felt like I was missing out on loading times and overall performance.