GeForce 8800 Ultra vs Radeon HD 7770

Intro

Compare those specifications to the Radeon HD 7770, which features core speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 640 SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
GeForce 8800 Ultra		171 Watts
	Difference: 91 Watts (114%)

Memory Bandwidth

As far as performance goes, the GeForce 8800 Ultra should in theory be much superior to the Radeon HD 7770 overall. (explain)

GeForce 8800 Ultra		103680 MB/sec
Radeon HD 7770		72000 MB/sec
	Difference: 31680 (44%)

Texel Rate

The Radeon HD 7770 should be a bit (about 2%) better at anisotropic filtering than the GeForce 8800 Ultra. (explain)

Radeon HD 7770		40000 Mtexels/sec
GeForce 8800 Ultra		39168 Mtexels/sec
	Difference: 832 (2%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 7770 is the winner, not by a very large margin though. (explain)

Radeon HD 7770		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 largest amount of information (measured in megabytes per second) that can be moved past the external memory interface in one second. It is calculated by multiplying the card's bus width by its memory speed. If it uses DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's 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 amount of texture map elements (texels) that are processed in one second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.