Radeon HD 4850 X2 512MB vs Radeon HD 6570 (OEM) 2GB

Intro

The Radeon HD 4850 X2 512MB has a core clock frequency of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Compare all of that to the Radeon HD 6570 (OEM) 2GB, which uses a 40 nm design. AMD has clocked the core frequency at 650 MHz. The GDDR5 RAM works at a speed of 1000 MHz on this specific model. It features 480 SPUs along with 24 Texture Address Units and 8 Rasterization Operator Units.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the largest amount of data (measured in megabytes per second) that can be transferred across the external memory interface in one second. It is calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.