Will lack of PSU power causes GPU not to run at 100% usage?

[Sebestian Fyx]

Like what the title said... Will it cause gpu not to run at 100%?

 

[leeb2013]

No but vsync or lack of cpu performance will

 

[Sebestian Fyx]

No but vsync or lack of cpu performance will

I running i7 4770 with SLI GTX 780 ti but when I'm playing bf4 MSI Afterburner shows that both my GPU usage for both GPU is only 50-70%. Am i facing bottleneck? FYI I'm running on 850watts only

 

[retix]

PSU model?