OCC has published a review on the VisionTek 4850 1GB B2

Overall, the VisionTek 4850 1GB B2 performed decently, although overclocking potential is limited. The core ran cool thanks to the Accelero L2, and the power circuits even had a small heat sink. This video card is easily installed into most systems with its wide array of connections: HDMI, VGA and DVI. The VisionTek B2 video card has a basic package, but for a midrange card it is adequate, and nothing really stands out as lacking.

VisionTek 4850 1GB B2 Review