Reportedly, both offerings will feature 320 stream processors-just like today's Radeon HD 3850 and 3870-but with memory interfaces only 128 bits wide. Core clock speeds will range up to 750MHz for the Radeon HD 4670, while memory will top out at 1,000MHz (presumably an "effective" 2,000MHz).

The spec sheet mentions 480 gigaFLOPS, 32GB/s of memory bandwidth, and a 59W power envelope for the 4670, compared to a respective 429 gigaFLOPS, 53GB/s, and 95W for the Radeon HD 3850. As for the 4650, that card will crank out a tamer 384 gigaFLOPS with up to 21.3GB/s of memory bandwidth. Assuming those specs didn't originate from a demented homeless man, the Radeon HD 4670 could turn out to be a fairly potent low-end offering.

Very loose numbers I agree.