I was looking around at candlepowerforums.com and I saw this:

http://www.luminus.com/content1520

High Output – 3600 lumens (6500K at high efficiency) or as much as 6000 lumens (6500K at high output)
Large, single chip with an emitting surface area of 5.4 mm2
High thermal conductivity package with a package thermal resistance of only 0.96° C/W
Integrated thermistor allows for real-time monitoring of the LED’s temperature
Lumen maintenance of greater than 70% after 60,000 hours
Variable drive current from less than 1 A to 6.3 A
Available in a variety of Correlated Color Temperatures (CCT’s) per ANSI C78-377-2008
Designed with a standard on-board connector