The ROG Ally X supports an M.2 2280 SSD, which is the same size that you'll find in most laptops and desktops. It only supports M.2 2280, so you can't put in a smaller SSD.

The ROG Ally comes with a Micron 2400 512GB m.2 NVMe Gen 4 SSD installed. There isn't a lot of room for game data on this SSD, so it's a good idea to upgrade to a higher-capacity SSD if possible.

Buy a new SSD As for your replacement SSD, you’ve got plenty of options. But which one you should get depends on how much storage you’ll need, and which ROG Ally you have.

Upgrading the storage of the ROG Ally with a full-size 2TB M.2 SSD is a task that can be accomplished with relative ease, thanks to the availability of a new 2230 to 2280 adapter board.

After you’ve connected the new SSD, you’ll also want to factory reset your ASUS ROG Ally, so that you can set up your ASUS ROG Ally afresh. No products found.

Now you're good to play your ROG Ally with the new WD_Black SN770M SSD installed. If you encounter any issues during the WD_Black SSD installation process, reach out to Western Digital customer ...

One thing to note is that the Asus ROG Ally X price is higher than the original device, coming in at £799 / $799 / AU$1599, compared to the first handheld costing £699 / $699 / AU$1299.