We tested storage using CrystalDiskMark at default NVMe Settings
Zotac Zone
The included SSD (FORESEE XP2000F512G) features the Silicon Motion SM2269XT controller, often used for DRAM-less SSDs, and two flash chips made by Longsys. It's a PCIe 4.0 unit but far from the fastest PCIe 4.0 SSD we've seen. Still, it's fast enough for gaming purposes, and while it doesn't include DRAM it supports HMB (64 MB buffer).
ASUS ROG Ally
The SSD inside our ROG Ally has a bit faster reading performance, but it's also much slower when it comes to sequential writing.
Here, too, we tested using CrystalDiskMark with default settings, the SD card is a 128 GB Samsung Pro Plus.
The UHS-II microSD card slot works well, and we got pretty solid numbers.