Hi guys, recently purchased the 16GB version of the Ultra Fit.
The reason this device is overheating is due to power draw via the USB 3.0 interface. I ran CrystalDiskMark with this drive sitting on a USB 3.0 port, and then a 2.0 port (both connected to motherboard on laptop).
When hooked up to USB 3.0 the Ultra Fit got ridiculously hot, to the point at which it felt like the end of a hot glue gun. When connected to USB 2.0 it was STILL HOT but tolerable.
Scores for USB 3.0:
Sequential Read 125.685 MB/s
Sequential Write 34.706 MB/s
Random Read 4KiB : 5.780 MB/s
Random Write 4KiB : 1.553 MB/s
Scores for USB 2.0:
Sequential Read : 41.072 MB/s
Sequential Write : 25.743 MB/s
Random Read 4KiB : 5.357 MB/s
Random Write 4KiB : 1.712 MB/s
According to the scores it appears that on USB 2 the drive takes a massive hit on Reading, but Writing and 4K R/W is actually fairly similar. THIS IS DUE TO THE POWER DRAW.
Therefore, I would use USB 2.0 if transferring large files- the transfer rate will be slower but heat will be tolerable. For small files transferring via USB 3.0 would be far quicker, though less safe.
Its a brutal shame that SanDisk markets a drive for USB 3 that can pretty much be only be safely used with USB 2.0. SanDisk needs to find a balance between the two.