Radeon HD 4770 is equipped with 512MB of GDDR5 memories clocked at 800MHz while Radeon HD 4750 is equipped with 1GB GDDR3 memories. Core clocks for both cards stood at 700MHz. The RV740 cards will be the first series from AMD to feature Triple-Phase power solution for more efficient power design.
CJ let us know that Radeon HD 4770 is expected to be priced at ~US$119 targeting GeForce GTS 240 while HD 4750 is expected to be priced at ~US$99 targeting GeForce 9600 GT.

http://vr-zone.com/articles/-rumor-a....html?doc=6579