Originally posted by mt3517475:

SD micro disks

Why doesn't steam deck sell their own approved sd micro disks that are proven to work. Instead of people buy the wrong one.

Which micro SD cards are the wrong ones?

There are few that have to fit a specific categories that make it run smother. What those are I'm still looking into it more. Good luck

These refer to sizing: SD<SDHC<SDXC

UHS is bus speed. 1 is slow, 3 is fast.

What more is needed?

Originally posted by mt3517475:

There are few that have to fit a specific categories that make it run smother. What those are I'm still looking into it more. Good luck

You are looking for an application performance class 2 card with a higher V rating(new version of U rating). These are marked with an A2 on them.

The A rating is about random read/write performance, the V rating is about minimum speed rating of the card itself for sequential operations.

A2 V30(also could be marked U3, same thing) cards are common, but if you want even better performance, a V60 would be nice but a massive upcharge. That's all there is to it.

Originally posted by rawWwRrr:

These refer to sizing: SD<SDHC<SDXC

UHS is bus speed. 1 is slow, 3 is fast.

What more is needed?

Steam deck and 99% of "high speed" devices are UHS-1 devices. Bus speed also does not actually affect card performance, just the speed at which the device can operate, and what the card is theoretically compatible with. Like pci generations and features don't actually tell you how fast the thing you plug in actually works at.
https://eo.steamhost.cc/steamdeck

UHS-I supports SD, SDXC and SDHC

UHS-2/3 are also being deprecated with the new SD express, with the only fallback mode being UHS-1, due to how uhs 2/3 connect.