GeForce 8800 GTS (G80) 640MB vs Radeon HD 6770

Intro

Compare all that to the Radeon HD 6770, which has GPU clock speed of 900 MHz, and 512 MB of GDDR5 memory running at 1050 MHz through a 128-bit bus. It also is made up of 800 Stream Processors, 40 TAUs, and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770		108 Watts
GeForce 8800 GTS (G80) 640MB		143 Watts
	Difference: 35 Watts (32%)

Memory Bandwidth

Theoretically, the Radeon HD 6770 should perform a little bit faster than the GeForce 8800 GTS (G80) 640MB in general. (explain)

Radeon HD 6770		67200 MB/sec
GeForce 8800 GTS (G80) 640MB		63360 MB/sec
	Difference: 3840 (6%)

Texel Rate

The Radeon HD 6770 should be quite a bit (about 46%) better at anisotropic filtering than the GeForce 8800 GTS (G80) 640MB. (explain)

Radeon HD 6770		36000 Mtexels/sec
GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
	Difference: 11376 (46%)

Pixel Rate

The Radeon HD 6770 should be a lot (approximately 40%) better at full screen anti-aliasing than the GeForce 8800 GTS (G80) 640MB, and also will be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 6770		14400 Mpixels/sec
GeForce 8800 GTS (G80) 640MB		10260 Mpixels/sec
	Difference: 4140 (40%)

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 information (counted in MB per second) that can be transported over the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory speed. If it uses DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better 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 can be applied per second. This figure is calculated 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 per second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called 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, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.