2x4... but my tent is actually 2'4"x4'4" so closer to 10 sq ft than 8.
People are always comparing 1000w HPS to a lower watt LED, usually around 600-640w which doesn't always give definitive results... but getting near equal results with +300 watts less is a big deal for some. I'm more into getting as many grams in as small a space as possible and consider 40w per foot and minimum 120 LPW by input to be the minimum as a 'hobby grower' otherwise there's no advantage over HID. Large scale growers might see advantage in going as low as 25 watts per foot, but the efficiency still needs to be similar to the larger HID bulbs. Most of the LED lamps that people have been suckered into buying have poor efficiency, in many cases comparable to CFL.
I would like to see watt for watt grow offs, either 600 vs 600 or 1000 vs 1000, but to my knowledge there aren't any yet.
If someone wanted to do a watt for watt with existing retail products, a 1000w -vs- 6 Area51 150w units. Spend $2400 on the LED and that can happen... which is why large scale growers are slow to adopt. Not just that but there are only a few LED lamp manufacturers that can compete in that category and a whole lot of people got turned of by cheap Chinese lights so there's that bad experience LED needs to shrug off. COBs are fairly new technology and only one company offering so far, soon to be two. In the next year or so there will be some interesting grow data coming in I expect. Eventually someone will do watt for watt grow offs. Beyond that it's just a matter of getting past the sticker shock.
. Or Illumitex. Or the fact that BML were basically as full of shit as anyone and they wore out that name. LOL RIP Busta's Makin' Lumens.
