The XFX GeForce9800GTX Black Edition card has a clock speed of 760MHz, which is a 85MHz overclock of the standard 9800GTX clock speed of 675MHz, a 20MHz overclock of the XT Edition and a 40MHz overclock of the XXX Edition. The Shader clock of 1900MHz compares quite favorably with the Shader Clock of 1698MHz of the standard 9800GTX, 1850MHz of the XXX and 1800MHz of the XT Edition from XFX.



Look here for the details, s'il vous plait.

Some interesting data-thanks.