GeForce 9800 GTX vs Radeon HD 4850 2GB

Intro

The GeForce 9800 GTX has clock speeds of 675 MHz on the GPU, and 1100 MHz on the 512 MB of GDDR3 memory. It features 128 SPUs along with 64 Texture Address Units and 16 Rasterization Operator Units.

Compare that to the Radeon HD 4850 2GB, which comes with clock speeds of 625 MHz on the GPU, and 993 MHz on the 2048 MB of GDDR4 memory. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of data (counted in MB per second) that can be transported over the external memory interface in a second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the 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 texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.