it mean your 3d clocks or best performance setting will use 1.24v allowing you clocks up to 600/800 in some cases. It will increase the cards temperature too.
http://www.newegg.com/Product/Produc...82E16820231129
There is the link, i wonder if its true and if there is any difference in performance :P
http://www.gskill.com/indexen.html