One item to recall. The ROP/Shader clock makes jumps. On the older GTX, it was in 27 MHz increments. You would go to the closer value on the core, +/-13 Mhz.

Using the previous example,

at 650, the ROP/Shader should be at 648. At 690, the ROP would be 702. The delta was used to keep the core geometry clock around 40 Mhz (and at least 27 Mhz) higher than the ROP/Shader component. The new 7900 uses a 50 Mhhz delta, which makes sense, since the core clocks are just that much higher. Stock clocks are now 700-648. The EVGA SC follows the old rule, and uses 740-702. The XFX at 690 will now do just 705-702, which means the fill bandwidth may exceed the core capacity and possibly underwork the ROP/Shader cores compared to what they could really handle. Following these proportions, memory bandwidth to handle the 702 ROP/Shader should be 1.73 GHz versus the 1.6 ghz at stock. The EVGA just looks to be a little better tuned, with 690(740-702) on the core and 1760 on the memory.