Kioxia U365 256GB USB Flash Drive Reviewed

Kioxia’s U365 flash drive is what I’d describe as “big, but slow.” Weighing in at 256GB the drive I tested is far beyond the capacity you might need for “sneaker net” transporting of files between computers.

I decided to use it with Ventoy, instead. And it’s actually really, really useful.

But first. The elephant in the room with the U365 is *write* speed- it’ll happily copy up to around 1GB at a fairly decent speed before it saturates and slows to a “crawl”. This is a mixed bag for copying ISO files for OS installation – which range from the 5.8GB of Windows 10 down to a comparatively svelte 2.0GB for Linux Mint. Copying Pop! OS 21.10 – for example – took around 2 minutes with the first third taking roughly 2 seconds and clocking in at some 40MB/s.

And this is about as *sequential* as it gets. This isn’t a particularly long time in the grand scheme of things, but when Kioxia’s own UHS-I SD card can do this same copy in half the time it does make you wonder what the poor USB drive did to deserve second-class treatment. Writing multiple smaller files such as – for example – a collection of ROMs (who, what, no, no collections here) will take what can only be described as an excruciating amount of time and I’d expect copying photos to strike something of a balance between these two extremes.

While copying anything larger than a few gigs will require far too much patience than I have available, and multiples of anything smaller than a few megabytes more time than there’s left in the universe- the U365 is great for things that fall between the two.

I currently have Windows 10, three versions of Pop OS, Linux Mint, Arch + KDE Neon, OPNsense, and Ubuntu ISOs copied straight onto the drive and an installation of Ventoy that makes it trivial – IE: presents a boot menu – to boot any of the ISOs for installation. For this, the U365 excels- it’s more than fast enough to make booting into and installing various Live CD distributions a breeze.

The generous capacity – albeit I know there are 1TB microSD cards now, what the heck!? – means you can keep throwing OS ISOs at it for the next few years without ever having to worry about cleaning up after yourself. Granted your Ventoy boot menu might get a bit… unmanageable.

Right now I’m using just under 40GB of the 249.9 GB formatted capacity (a small amount is given over to Ventoy’s boot partition) between install ISOs, music from my bandcamp purchases, ROMs, a full backup of my StarLite, a smattering of installers that are no-doubt already out of date, and some compressed – note what I said about copying multiple tiny files – backups of various Raspberry Pi SD cards.

The U365 is a little chonky, mostly because it uses the “retractable USB connector” gimmick that I’m not sure really offers any actual protection. Cruft is going to get into the port whether it’s retracted or not. It’s also a little creaky when you squeeze it. By far not the fanciest or most well built of flash drives it’s a little of a juxtaposition with its fairly premium 256GB capacity. It’s not bad, by any stretch of the imagination, but there are surely better options out there that fit your storage into something a little more rugged.