Radeon HD 4550 512MB vs Radeon HD 6870

Intro

The Radeon HD 4550 512MB makes use of a 55 nm design. AMD has clocked the core speed at 600 MHz. The GDDR3 memory works at a frequency of 800 MHz on this particular card. It features 80(16x5) SPUs along with 8 Texture Address Units and 4 Rasterization Operator Units.

Compare those specs to the Radeon HD 6870, which has a clock speed of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also features a 256-bit memory bus, and makes use of a 40 nm design. It features 1120 SPUs, 56 Texture Address Units, and 32 Raster Operation Units.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of information (in units of megabytes per second) that can be transferred across the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If it uses DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.