The models based on the RV710 chip are Radeon 4550HD and Radeon 4350HD and not HD 4450/4470 as assumed earlier. The difference between the two models is in the memory, as the model 4550 HD is going to be using DDR3 which runs on 800 MHz. The fast RAM memory will compensate for the narrow 64 bit bus. RAdeon 4350 HD is going to have DDR2 RAM with 256 MB of memory, the frequency is not yet known. nVidia Gefore 9400GT DDR2 on the other hand has 128 bit bus but the freuency of the DDR2 is 400 MHz. So the benchmarks were done in 3DMark Vantage and 3DMark 06. The results of all the test show clear supremacy of the Radeon HD 4550. Radeon models gonna show up on the market in November.
It will become more interesting with other benchmarks, as 3DMark are ATI-dominated in general and in no way reflects real-life performance. I’m looking forward to hear about prices, as the 4570 is already really cheap at $70 or so, so how low are they going to price those cards?! $40 and $55?
I can only speculate at this point.