GeForce 8800 GTS (G80) 640MB vs Radeon HD 6770 1GB

Intro

Compare those specifications to the Radeon HD 6770 1GB, which uses a 40 nm design. ATi has set the core speed at 900 MHz. The GDDR5 memory works at a frequency of 1050 MHz on this particular model. It features 800 SPUs as well as 40 Texture Address Units and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770 1GB		108 Watts
GeForce 8800 GTS (G80) 640MB		143 Watts
	Difference: 35 Watts (32%)

Memory Bandwidth

Performance-wise, the Radeon HD 6770 1GB should in theory be a small bit superior to the GeForce 8800 GTS (G80) 640MB overall. (explain)

Radeon HD 6770 1GB		67200 MB/sec
GeForce 8800 GTS (G80) 640MB		63360 MB/sec
	Difference: 3840 (6%)

Texel Rate

The Radeon HD 6770 1GB will be a lot (about 46%) better at anisotropic filtering than the GeForce 8800 GTS (G80) 640MB. (explain)

Radeon HD 6770 1GB		36000 Mtexels/sec
GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
	Difference: 11376 (46%)

Pixel Rate

The Radeon HD 6770 1GB will be much (about 40%) better at AA than the GeForce 8800 GTS (G80) 640MB, and also should be capable of handling higher screen resolutions without slowing down too much. (explain)

Radeon HD 6770 1GB		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: Memory bandwidth is the largest amount of information (in units of MB per second) that can be transferred over the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs 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 rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.