Think about what the sun is..... The sun is what you want to create. There is no light in the world that can match the sun.
I hope you're not talking intensity? Regarding spectrum, there's alot of hooey on that one too. I don't think the plant cares as I've grown very high yielding skunk with only HPS from start to finish. Those saying otherwise have not done their homework and are parroting what someone heard or read at the lighting section of a Hydro vendor's website. HPS does contain the blue spectrum. MH does contain the red spectrum, plenty enough to produce very nice productive plants.
Even a 250W hps is brighter than the sun if you measure close enough. Stop the "we and us said" chest beating people, learn botany, and do the measurements. I did, and here they are:
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Footcandle light values are given for a 250W Phillips HPS and an Osram Super 600W HPS, both taken from the centerpoint of the bulb/bottom of a white enameled, horizontal Diamond Lights reflector having a typical gull wing insert.
DISTANCE FROM LIGHT........F.C. READING
........................
250 Watt..................
600 Watt
Within 6" of lamps (way over the 10K f.c. mark)
6".......................10,000.....................10K+
8".......................7,100.......................10K+
12"......................4,800......................8,700
18"......................2,800......................5,600
24"......................2,000......................4,200
30"......................1,400......................3,300
Frame of reference: sun = 9,000 - 10,000f.c. average, clear day at high noon
Regular Cool White shop fluor measured 2" from bulb = 1,200 f.c.