Radeon HD 4870 1GB vs Radeon HD 6670 (OEM)

Intro

The Radeon HD 4870 1GB makes use of a 55 nm design. AMD has clocked the core speed at 750 MHz. The GDDR5 memory is set to run at a frequency of 900 MHz on this particular model. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Compare that to the Radeon HD 6670 (OEM), which features GPU clock speed of 800 MHz, and 512 MB of GDDR5 memory running at 1000 MHz through a 128-bit bus. It also features 480 SPUs, 24 TAUs, and 8 ROPs.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of data (in units of megabytes per second) that can be moved across the external memory interface within a second. It is worked out by multiplying the interface width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total number of texture units by the core clock 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 in one second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the clock 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 output rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.