I have some questions about the technical specification of the
ASUS EAH4850 TOP/HTDI/512M Radeon HD 4850 512MB graphics card.
1. What is the maximum computational power of this GPU?
2. What is the maximum memory bandwith?
You can find the information you seek and a lot more at http://www.amd.com/us/products/desktop/graphics/ati-radeon-hd-4000/hd-4850/Pages/ati-radeon-hd-4850-specifications.aspx
Remember this card is only OpenCL 1.0 compliant. The memory bandwidth depends on the number of memory channels the device has the technology used.(You can see this value in CCC).
As of computational power, IIRC, this device has 800stream processors, so it should be slightely above 1TFLOPS(depends on the clock).