Radeon HD 4870 2GB vs Radeon HD 6750

Intro

The Radeon HD 4870 2GB makes use of a 55 nm design. AMD has set the core frequency at 750 MHz. The GDDR5 memory is set to run at a frequency of 900 MHz on this specific card. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Compare that to the Radeon HD 6750, which makes use of a 40 nm design. AMD has clocked the core speed at 725 MHz. The GDDR5 memory works at a frequency of 1000 MHz on this particular model. It features 720 SPUs as well as 36 Texture Address Units and 16 Rasterization Operator Units.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the largest amount of data (in units of megabytes per second) that can be moved across the external memory interface within a second. The number is worked out by multiplying the bus width by the speed of its memory. In the case of DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's 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 applied in one second. This figure is calculated by multiplying the total texture units of the card 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 one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.