Radeon HD 4670 1GB vs Radeon HD 6770

Intro

The Radeon HD 4670 1GB has a core clock speed of 750 MHz and a GDDR4/GDDR3/DDR3/DDR2 memory frequency of 1100 MHz. It also makes use of a 128-bit bus, and makes use of a 55 nm design. It is comprised of 320(64x5) SPUs, 32 Texture Address Units, and 8 Raster Operation Units.

Compare all of that to the Radeon HD 6770, which has a GPU core clock speed of 900 MHz, and 512 MB of GDDR5 RAM set to run at 1050 MHz through a 128-bit bus. It also features 800 SPUs, 40 Texture Address Units, and 16 ROPs.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of data (counted in MB per second) that can be transported across the external memory interface in one second. It is worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at 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 could possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.