No you are wrong wii can not do 360 graphics.
The clock speed is too low.
(but nobody knows the official stats of the graphics card)
wiki says;
* CPU: PowerPC-based "Broadway" processor, made with a 90 nm SOI CMOS process, reportedly† clocked at 729 MHz[83]
* GPU: ATI "Hollywood" GPU made with a 90 nm CMOS process,[84] reportedly† clocked at 243 MHz[83]
†None of the clock rates have been confirmed by Nintendo, IBM, or ATI.