Both of the cards [the 8400GS-256 and 8400GS-128] run at a 450-MHz core clock and an 850-MHz memory clock. Both also use a 64-bit memory interface, which place them on the low end of the Nvidia 8-series performance spectrum. However, the 8400GS chip supports resolutions of 2560 x 1600, as well as DX10 and HDR.
The cards will come with a three-year warranty from Foxconn. Besides the sub-$100 price tag, the company did not announce specific pricing or shipping information.