GeForce 8800 Ultra vs Radeon HD 4890 2GB

Intro

Compare those specs to the Radeon HD 4890 2GB, which uses a 55 nm design. AMD has set the core frequency at 1000 MHz. The GDDR5 RAM works at a speed of 975 MHz on this particular model. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 Ultra		171 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 19 Watts (11%)

Memory Bandwidth

Performance-wise, the Radeon HD 4890 2GB should theoretically be just a bit superior to the GeForce 8800 Ultra in general. (explain)

Radeon HD 4890 2GB		124800 MB/sec
GeForce 8800 Ultra		103680 MB/sec
	Difference: 21120 (20%)

Texel Rate

The Radeon HD 4890 2GB should be just a bit (approximately 2%) better at anisotropic filtering than the GeForce 8800 Ultra. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
GeForce 8800 Ultra		39168 Mtexels/sec
	Difference: 832 (2%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 4890 2GB is superior to the GeForce 8800 Ultra, though not by far. (explain)

Radeon HD 4890 2GB		16000 Mpixels/sec
GeForce 8800 Ultra		14688 Mpixels/sec
	Difference: 1312 (9%)

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 max amount of data (measured in megabytes per second) that can be transported past the external memory interface in a second. The number is worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better 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 texture map elements (texels) that are applied per second. This number is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends 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.