GeForce 8800 GT 256MB vs Radeon HD 6790

Intro

Compare that to the Radeon HD 6790, which makes use of a 40 nm design. AMD has set the core speed at 840 MHz. The GDDR5 RAM works at a speed of 1050 MHz on this particular model. It features 800 SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 GT 256MB		105 Watts
Radeon HD 6790		150 Watts
	Difference: 45 Watts (43%)

Memory Bandwidth

The Radeon HD 6790, in theory, should be much faster than the GeForce 8800 GT 256MB in general. (explain)

Radeon HD 6790		134400 MB/sec
GeForce 8800 GT 256MB		44800 MB/sec
	Difference: 89600 (200%)

Texel Rate

Both cards have the exact same texel fill rate, so theoretically they should perform equally good at at anisotropic filtering. (explain)

Pixel Rate

The Radeon HD 6790 is quite a bit (about 40%) more effective at AA than the GeForce 8800 GT 256MB, and also should be capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 6790		13440 Mpixels/sec
GeForce 8800 GT 256MB		9600 Mpixels/sec
	Difference: 3840 (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 data (measured in megabytes per second) that can be transported over the external memory interface in one second. It is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The number 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 filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.