German website Hardware-Infos has obtained (translation here) what looks like an official document with "final" specifications, pricing information, and launch details for AMD's next-generation Radeon HD 4800-series graphics cards. This information echoes the June 18 launch date we heard last week, but it says both the 4850 and the 4870 will come out on the same day.
The Radeon HD 4850 will apparently feature 480 stream processors, a 625MHz core speed, an 825MHz shader speed, 512MB of 1143MHz GDDR3 memory, and a 114W thermal envelope. The faster Radeon HD 4870 will also have 480 SPs, but with an 850MHz core speed, 1050MHz shader speed, 1GB of 1935MHz (3870MHz "effective") GDDR5 RAM, and a 157W TDP. Both cards will also feature 256-bit memory buses and 16 raster operators, just like existing Radeon HD 3800-series models, but with twice as many texture mapping units (32 instead of 16).
Hardware-Infos says the Radeon HD 4850 will launch at $249 and the Radeon HD 4870 will be $349. If recently leaked performance numbers are accurate, the 4850 may be in the same playing field as Nvidia's ~$300 GeForce 9800 GTX.