GeForce 8800 Ultra vs Radeon HD 4890 1GB

Intro

Compare all of that to the Radeon HD 4890 1GB, which comes with a core clock speed of 1000 MHz and a GDDR5 memory speed of 975 MHz. It also makes use of a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 Ultra		171 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 19 Watts (11%)

Memory Bandwidth

Performance-wise, the Radeon HD 4890 1GB should theoretically be a bit better than the GeForce 8800 Ultra overall. (explain)

Radeon HD 4890 1GB		124800 MB/sec
GeForce 8800 Ultra		103680 MB/sec
	Difference: 21120 (20%)

Texel Rate

The Radeon HD 4890 1GB is just a bit (approximately 2%) better at AF than the GeForce 8800 Ultra. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
GeForce 8800 Ultra		39168 Mtexels/sec
	Difference: 832 (2%)

Pixel Rate

The Radeon HD 4890 1GB should be a little bit (approximately 9%) better at AA than the GeForce 8800 Ultra, and capable of handling higher resolutions without slowing down too much. (explain)

Radeon HD 4890 1GB		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: Memory bandwidth is the max amount of information (counted in MB per second) that can be transferred over the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, 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 texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka 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 - the lower the bandwidth is, the lower the potential to reach the max fill rate.