GeForce GTX 580 3GB vs Radeon HD 6990

Intro

Compare those specs to the Radeon HD 6990, which features a clock frequency of 830 MHz and a GDDR5 memory speed of 1250 MHz. It also makes use of a 256-bit memory bus, and uses a 40 nm design. It features 1536 SPUs, 96 TAUs, and 32 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 580 3GB		244 Watts
Radeon HD 6990		375 Watts
	Difference: 131 Watts (54%)

Memory Bandwidth

The Radeon HD 6990 should in theory be quite a bit faster than the GeForce GTX 580 3GB in general. (explain)

Radeon HD 6990		320000 MB/sec
GeForce GTX 580 3GB		192384 MB/sec
	Difference: 127616 (66%)

Texel Rate

The Radeon HD 6990 is a lot (more or less 223%) faster with regards to anisotropic filtering than the GeForce GTX 580 3GB. (explain)

Radeon HD 6990		159360 Mtexels/sec
GeForce GTX 580 3GB		49408 Mtexels/sec
	Difference: 109952 (223%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 6990 is the winner, by far. (explain)

Radeon HD 6990		53120 Mpixels/sec
GeForce GTX 580 3GB		37056 Mpixels/sec
	Difference: 16064 (43%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (counted in megabytes per second) that can be transferred over the external memory interface within a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type RAM, the result 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 AA, 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 amount of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.