I recently upgraded my XPS 8900 by adding a EVGA 650 G2 power supply. It did not increase the boot time, nor did I expect it too. I also tried upgrading my memory from 8 GB to 16 GB. It did not increase the boot time from the time I push the power button to login or from login to desktop. I am using a Samsung 850 EVO SSD. I am satisfied with the boot times and the general speed of the computer. But I am disappointed that it is not much faster than my XPS 8300. Both computers are using SSD's. I don't game, and use my computer mainly for word processing and the internet, but I do like a fast computer. The memory increase did improve the time it takes to launch the internet, VLC videos, Windows Live Mail, and the time it takes after you push administrative tools, computer management, storage and then the disks show up. Overall, I would say it is a 15% increase in speed, so for $37 it was worth it. I doubt it if using a Samsung 950 Pro PCIe NVMe would speed up boot times from what I have read, so I am not wasting my money. They were supposed to come out with a new version of SSD early this year, but I have yet to see it.