Theres actually a ton of journals out there with 315w 4x4 grows or similar where it seems like the average yield depending on grower and strain is roughly 10-14 ozs. Some guys have had runs as good as to pull nearly an entire lb with one 315w. I myself had a pretty successful run on my last harvest. Filling only two thirds of my 5x5 and using a 630w cmh, I was able to yield 700 grams total so 25 ozs of legit bud not adding in popcorn or shake buds. And if you would like I have pics of the entire way through flower as well as a pic of them all jarred up in 1 or 2 oz increments so the yield can be verified. I'm not going to make assumptions and be one of those growers who say if I had the tent completely filled I could of got this amount instead. But that's not accurate obviously. I could of fit 2 more plants probably at most and probably average a couple few zips each per plant. So that would of hopefully put me in range of 1.2 to 1.3 gpw ish. But I'm happy hitting my verified 700g using 630w. Anything close to a gpw is stellar run for me. I think alot of people probably exaggerate yields sometimes because I've seen grows that just dont seem capable of hitting REAL GPW ratio. So I always seem to have people trying to claim those are medioker numbers but at the end of the day as long as I'm satisfied that's really all that matters lol