Hey Dynamics, I can't imagine why KSP won't run on your system, I have the AMD 6 core version with the same Gcard fitted (HD 7770) and only 8Gb ram and mine runs fine (well except the odd crash now and again due to the ton of mods I have installed), but otherwise no problems. I must say I never run my games thru steam (found no use of steam in the background as of yet and if my mates wanna say "hi" then can damn well call me ;-))
1 tip I have for you (as I found it caused problems with other games) turn off Easy Tune if you have it running, see if that is the problem (altho I didn't hurt KSP on my rig, but totally screwed up World of Warships)
I would clear out a bunch of those processes that are running in the background tho they may not be helping the situation (anything steam, curse, origin) they will clog up your system.