Radeon HD 3870 1GB vs Radeon R9 M275X

Intro

The Radeon HD 3870 1GB comes with a core clock frequency of 775 MHz and a GDDR4 memory frequency of 1125 MHz. It also uses a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 320(64x5) SPUs, 16 TAUs, and 16 Raster Operation Units.

Compare all of that to the Radeon R9 M275X, which has clock speeds of 900 MHz on the GPU, and 1125 MHz on the 2048 MB of GDDR5 memory. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the largest amount of information (counted in megabytes per second) that can be moved across the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better 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 is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher this number, the better the video 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 amount of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.