Now that both the Radeon HD 4850 and Radeon HD 4670 are out, AMD has fiercely competitive, current-generation graphics cards at the $80 and $170 price points. That's all well and good, but it leaves a gaping hole right in the middle—and Nvidia is already playing there with its $130 GeForce 9800 GT.
According to VR-Zone, AMD is planning to fight back against the 9800 GT with a new Radeon HD 4830 graphics card. Quoting what seem to be leaked AMD slides, the site says that card will pack 640 stream processors, a 256-bit memory interface, and GDDR3 memory. By contrast, the 4850 has 800 SPs, while the 4670 has just 320 SPs and a 128-bit memory bus.
VR-Zone predicts the 4830 will appear in stores on October 21 with a sub-$150 price tag. The site has also posted slides that show the card handily outperforming the GeForce 9800 GT. Those seem to be AMD numbers, though, so we advise taking them with a grain of salt—especially considering the firm hasn't announced anything yet.