you don't need an SSD for gaming .. big deal you get 5 second windows startup. with no SSD more like 30, go make yourself a sandwich or something ..
Lol with an SSD your system is way faster too. Ask any computer enthusiast, an SSD in this kind of build is needed.
My own computer filled with games is slow as forget, all because me having only an HDD
An SSD isn't just for fast boot time, it makes a faster system in general, which also makes aster game loading times and such