That is completely, imo. I could have done the same on mine, but I have a lack of space and tbh, I think the external on top looks so much better for the CM690. If it were on the back, it would break off from getting bumped into all the time.
AMD Phenom II 965 125w 3.4ghz
G.Skill 4GB 1600mhz ddr3 ram
Asus M4A89GTD PRO/USB3 mobo
Corsair tx850w
thermaltake SpinQ CPU cooler
Raidmax smilodon case
Asus 24x dvd burner
8-1 card reader that i raped out of an old HP lol
500gb seagate barracuda
23" Hanns-g monitor
coming soon (actually on its way through UPS)
XFX HD5970 Black Edtion
i apologize for the wire management, its the best i could do with this case.