The Radeon HD 3670’s GPU/memory frequencies will both be 800 MHz versus the 800/700 for the Radeon HD 2600 XT GDDR3 and 800/1100 for the HD 2600 XT GDDR4. The Radeon HD 3650’s GPU will be set at 600 MHz like on the Radeon HD 2600 Pro; however, its memory will be increased to 500 MHz or 100 more. In both cases, the number of calculation and texturing units as well as ROPS remain unchanged. In short, we shouldn’t expect a revolution.
The interest for AMD is that the RV635 will be engraved in 55 nm versus 65 nm for the RV630. The chip is therefore smaller and allows lowering production costs. You may recall that previous information alluded to PCI-Express 2.0 interface and DirectX 10.1 support and the possible presence of a DisplayPort output. In terms of availability, the Radeon HD 3670 should arrive in January and the Radeon HD 3650 will be for the end of February.