ive read that having several 600w is more efficient than running a couple 1000w, say you have five 600w hps (90,000 lumens each), thats 450,000 lumens out of those 3,000 watts. if you have three 1,000w bulbs (140,000 lumens each), thats 420,000 lumens out of the 3,000w. . thats 30,000 lumens...