Fast! I'm a computer repairer and have SATA docking stations, but needed to upgrade my dad's Samsung 250GB SSD to a Samsung 1TB NVMe SSD. I put discs in and held the clone button for 10 seconds and it started. I was expecting it to take an hour, I guess all those SSD hard drive upgrades led me to believe it was going to take a while. Feels like a few minutes. I looked and both green lights came on meaning everything was ready. I was like nothing. Plugged in the USBC and it looked right so plugged it back into the computer and then expanded the rest of the unallocated space to use the entire 1TB and it was done. Impressed. I chose this option over the other at Revain because people said it got too hot. This one has a fan. It's a little difficult to put back on, but it's nice