600w lights ?? advice please?

iv got my three exo cheese plants in a 1.2 by 1.2 tent. iv had them under a 600w light all the way through they are on 5th week of bud... iv just been given another 600w light exactley the same by a friend ... my question is would it at all benefit putting them under two 600w lights instead of just one ???

if you can handle heat hell yeah it would be more benefit...