the 4890 is capable of 1GHz.
The only real advantage of the 4890 over the 5770 is that its on a 256-bit memory interface instead of 128-bit. Even so, the 40nm technology of the 5770 makes it overclock a bit easier, not to mention scale very nicely in crossfire.
The only real advantage of the 4890 over the 5770 is that its on a 256-bit memory interface instead of 128-bit. Even so, the 40nm technology of the 5770 makes it overclock a bit easier, not to mention scale very nicely in crossfire.