Rog Xbox Ally X SD card speed issue

[thundersha]

According to the tech specs, the card reader on this device has been upgraded to “UHS-I with DDR200”, which should theoretically allow certain high-speed microSD cards to reach close to 200 MB/s.
However, after testing multiple cards (SanDisk, Samsung, AGI — all 1 TB or 2 TB), almost all of them are capped at around 97 MB/s. When switching to an external USB card reader, the same cards can easily reach 150 MB/s, and some even hit around 170 MB/s.

All signs point to the built-in reader having trouble operating correctly in DDR200 mode. Is there any chance this could be addressed in a future driver, firmware, or BIOS update?

[Falcon2_ROG]

@thundersha 
Please provide me with the current BIOS version, system version, and OS build of your ALLY.
Also, please provide the full model number of the SD card you have tested along with the test screenshots.
Thank you.

[thundersha]

Hi @Falcon2_ROG :
BIOS 312 , system version Windows 11 Home 25H2 OS build 26200.7171 

- built-in reader
AGI Supreme Pro TF138 2TB 

Samsung PRO Plus 1TB

 
- external
AGI Supreme Pro TF138 2TB 

Samsung PRO Plus 1TB


DDR200 is a powerful features of this handheld. offers a simple way to expand large storage for indie games with good performance. really hope to see it working properly soon.

Thank you 🙂 

[Falcon2_ROG]

@thundersha 
I sent you a message, please check it.
Thank you.