Radeon HD 3650 512MB vs Radeon HD 7870

Intro

The Radeon HD 3650 512MB uses a 55 nm design. AMD has clocked the core frequency at 725 MHz. The GDDR3 memory is set to run at a frequency of 800 MHz on this particular model. It features 120(24x5) SPUs as well as 8 Texture Address Units and 4 Rasterization Operator Units.

Compare those specifications to the Radeon HD 7870, which comes with a clock frequency of 1000 MHz and a GDDR5 memory frequency of 1200 MHz. It also uses a 256-bit bus, and makes use of a 28 nm design. It is made up of 1280 SPUs, 80 Texture Address Units, and 32 ROPs.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of data (counted in megabytes per second) that can be transported over the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, 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 amount of texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total 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 in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.