This is almost a year old and I somehow totally missed it.
http://www.cree.com/News-and-Events/Cre ... ry/276-LPW
This means an easy knockout of any HPS lamp with a better balanced spectrum for quality. These are at a regular 350mA drive, which means these are effectively 1w diodes. I'd bet at 2w you would see efficiencies of roughly 230 lux/w. Either way, real-wattage implied, at 1w drive, you'd only need about 550w to truly replace 1,000w HPS, lumen or photon flux density-wise, and that could easily be done in a small form factor using CoB technology and a good cooling system. I would bet you could get the 230 lux/w rating at 1w with a better color spectrum balanced more towards the sun at 5600K, and at that, you'd still only need ~600w to beat an HPS at 1,000w.
How I love LED.