Will this actually fit my Steam Deck, ROG Ally, or MSI Claw?
Yes. This is the M.2 2230 version of the UD90, the same compact size as the factory drive in these handhelds. The standard-size UD90 (M.2 2280) will not physically fit any of these devices — make sure you're ordering this 2230 version specifically.
Will I get the full 5,000MB/s speed on my Steam Deck?
No, and that's not specific to this drive. The Steam Deck's internal M.2 slot is restricted to PCIe 3.0, so any Gen4 drive, including this one, runs at Gen3 speeds there. Independent testing found it performs well within that restriction. ROG Ally and MSI Claw support full PCIe Gen4, so you'll see closer to the rated speed on those devices.
Is the lower write speed on some capacities a dealbreaker for handheld gaming use?
No, for most handheld use. Handhelds spend most of their time reading game assets, not performing large sustained writes, which is where a lower write-speed rating matters most. If you frequently write very large files (video capture, large downloads in bulk), you'll notice the difference more than a typical gamer installing and playing titles.
Does this drive run hot inside a handheld's enclosed case?
Independent testing measured up to roughly 67°C under sustained PCIe 4.0 load on an open testbed, well below the ~83°C throttling threshold. Enclosed handheld cases can run somewhat warmer than open-air testing, but this is a normal, expected margin, not a cause for concern under typical use.
What capacity should I get?
1TB offers the best balance of price and performance, with confirmed 600TBW endurance in line for its capacity. 2TB is the best choice if you want to stop deleting and redownloading games regularly, at the cost of a lower write-speed rating than the 1TB model.
