Samsung also goes 1.5Tb, power friendly drives start shipping
 

The EcoGreen F2EG uses just three 500-gig platters, or one fewer than Seagate's 1.5TB Barracuda 7200.11. (Seagate does make 7200.12 drives with 500GB platters, but those only reach up to 1TB just now.)

Samsung boasts that the F2EG's power consumption is 40% lower at idle and 45% lower during seeks than "competing drives," so the lower platter count likely pays dividends. Since official spec sheets don't seem to mention the EcoGreen's spindle speed, though, one can probably assume those platters run at less than 7,200 RPM—like those of Western Digital's Caviar Green series.

http://techreport.com/discussions.x/16552