GeForce 8800 GTS (G80) 640MB vs Radeon HD 4850 512MB

Intro

The GeForce 8800 GTS (G80) 640MB uses a 90 nm design. nVidia has clocked the core frequency at 513 MHz. The GDDR3 memory works at a frequency of 792 MHz on this particular card. It features 96 SPUs as well as 48 Texture Address Units and 20 Rasterization Operator Units.

Compare those specifications to the Radeon HD 4850 512MB, which makes use of a 55 nm design. AMD has clocked the core frequency at 625 MHz. The GDDR3 memory runs at a frequency of 993 MHz on this model. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of data (measured in MB per second) that can be transported past the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This number is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.