i am purchasing this one, is it good for OC ? and rest of the system performance? is it sufficient ??
As I told you, 450W is plenty with a 1080, 550W for a 1080 Ti. The 650W one won't give you any benefits (unless you like noise, in which case the TX650M is noisier). I've also told you my recommendations, but if none of those are available at decent prices, the TXM is good.