Radeon HD 4670 1GB vs Radeon HD 7770

Intro

The Radeon HD 4670 1GB features a GPU core clock speed of 750 MHz, and the 1024 MB of GDDR4/GDDR3/DDR3/DDR2 RAM is set to run at 1100 MHz through a 128-bit bus. It also is comprised of 320(64x5) Stream Processors, 32 Texture Address Units, and 8 Raster Operation Units.

Compare those specs to the Radeon HD 7770, which features clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 memory. It features 640 SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (in units of megabytes per second) that can be moved across the external memory interface within a second. It's worked out by multiplying the bus width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the graphics card will be at 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 could possibly write to its local memory in one second - measured in millions of pixels per second. The figure 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 is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.