GeForce GTX 580 vs Radeon HD 4850 X2 1GB

Intro

Compare that to the Radeon HD 4850 X2 1GB, which has GPU core speed of 625 MHz, and 1024 MB of GDDR3 RAM set to run at 993 MHz through a 256-bit bus. It also is made up of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 580		244 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 6 Watts (2%)

Memory Bandwidth

The GeForce GTX 580, in theory, should perform a lot faster than the Radeon HD 4850 X2 1GB overall. (explain)

GeForce GTX 580		192384 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 65280 (51%)

Texel Rate

The Radeon HD 4850 X2 1GB should be just a bit (approximately 1%) more effective at texture filtering than the GeForce GTX 580. (explain)

Radeon HD 4850 X2 1GB		50000 Mtexels/sec
GeForce GTX 580		49408 Mtexels/sec
	Difference: 592 (1%)

Pixel Rate

The GeForce GTX 580 is a lot (more or less 85%) more effective at anti-aliasing than the Radeon HD 4850 X2 1GB, and capable of handling higher screen resolutions while still performing well. (explain)

GeForce GTX 580		37056 Mpixels/sec
Radeon HD 4850 X2 1GB		20000 Mpixels/sec
	Difference: 17056 (85%)

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 maximum amount of information (measured in megabytes per second) that can be moved across the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.