Radeon HD 3870 1GB vs Radeon R9 M275X

Intro

The Radeon HD 3870 1GB has a clock frequency of 775 MHz and a GDDR4 memory frequency of 1125 MHz. It also features a 256-bit memory bus, and makes use of a 55 nm design. It features 320(64x5) SPUs, 16 Texture Address Units, and 16 ROPs.

Compare all that to the Radeon R9 M275X, which comes with a clock frequency of 900 MHz and a GDDR5 memory speed of 1125 MHz. It also features a 128-bit bus, and uses a 28 nm design. It features 640 SPUs, 40 TAUs, and 16 ROPs.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (measured in megabytes per second) that can be transported across the external memory interface within a second. The number is calculated by multiplying the interface width by the speed of its memory. In the case of DDR type memory, the result should 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 number of texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.