So, i use linux with kde and was copying some gigabytes of files from a smartphone to a usb device and while doing that the system monitor kept showing that it was writing some mb/s and i got curious, is said writing happening to my ssd or is it just talking about the usb drive?
For files on your phone transferred via MTP, when you open a file directly, it copies it to a temporary folder then you can play the file or open the document, then delete them after you close/disconnect. So transferring files might copy it to the temp folder on your SSD first before moving it.