GeForce 8800 Ultra vs Radeon HD 6850

Intro

Compare that to the Radeon HD 6850, which has GPU clock speed of 775 MHz, and 1024 MB of GDDR5 memory set to run at 1000 MHz through a 256-bit bus. It also features 960 Stream Processors, 48 TAUs, and 32 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6850		127 Watts
GeForce 8800 Ultra		171 Watts
	Difference: 44 Watts (35%)

Memory Bandwidth

In theory, the Radeon HD 6850 should perform a lot faster than the GeForce 8800 Ultra overall. (explain)

Radeon HD 6850		128000 MB/sec
GeForce 8800 Ultra		103680 MB/sec
	Difference: 24320 (23%)

Texel Rate

The GeForce 8800 Ultra will be a small bit (more or less 5%) more effective at texture filtering than the Radeon HD 6850. (explain)

GeForce 8800 Ultra		39168 Mtexels/sec
Radeon HD 6850		37200 Mtexels/sec
	Difference: 1968 (5%)

Pixel Rate

The Radeon HD 6850 should be a lot (approximately 69%) more effective at FSAA than the GeForce 8800 Ultra, and capable of handling higher screen resolutions without losing too much performance. (explain)

Radeon HD 6850		24800 Mpixels/sec
GeForce 8800 Ultra		14688 Mpixels/sec
	Difference: 10112 (69%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the largest amount of data (counted in megabytes per second) that can be transferred past the external memory interface within a second. It is calculated by multiplying the bus width by its memory speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster 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 are processed in one second. This is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.