Radeon HD 4670 1GB vs Radeon HD 7770

Intro

The Radeon HD 4670 1GB has a GPU core clock speed of 750 MHz, and the 1024 MB of GDDR4/GDDR3/DDR3/DDR2 memory 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 makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 RAM is set to run at a frequency of 1125 MHz on this particular model. It features 640 SPUs as well as 40 Texture Address Units and 16 ROPs.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (counted in megabytes per second) that can be transferred across the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 number of texture map elements (texels) that can be applied in one second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write 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 card's 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 rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.