Radeon HD 4850 X2 512MB vs Radeon HD 6770

Intro

The Radeon HD 4850 X2 512MB makes use of a 55 nm design. AMD has clocked the core speed at 625 MHz. The GDDR3 RAM works at a frequency of 993 MHz on this particular card. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Compare those specs to the Radeon HD 6770, which has GPU core speed of 900 MHz, and 512 MB of GDDR5 memory set to run at 1050 MHz through a 128-bit bus. It also features 800 Stream Processors, 40 TAUs, and 16 ROPs.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (counted in MB per second) that can be moved over the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.