GeForce GTX 580 3GB vs Radeon HD 4870 2GB

Intro

Compare all that to the Radeon HD 4870 2GB, which features a clock frequency of 750 MHz and a GDDR5 memory speed of 900 MHz. It also uses a 256-bit bus, and uses a 55 nm design. It features 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 2GB		150 Watts
GeForce GTX 580 3GB		244 Watts
	Difference: 94 Watts (63%)

Memory Bandwidth

In theory, the GeForce GTX 580 3GB should be 67% quicker than the Radeon HD 4870 2GB in general, due to its higher data rate. (explain)

GeForce GTX 580 3GB		192384 MB/sec
Radeon HD 4870 2GB		115200 MB/sec
	Difference: 77184 (67%)

Texel Rate

The GeForce GTX 580 3GB should be a lot (approximately 65%) more effective at texture filtering than the Radeon HD 4870 2GB. (explain)

GeForce GTX 580 3GB		49408 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 19408 (65%)

Pixel Rate

The GeForce GTX 580 3GB should be much (about 209%) more effective at AA than the Radeon HD 4870 2GB, and also will be capable of handling higher resolutions while still performing well. (explain)

GeForce GTX 580 3GB		37056 Mpixels/sec
Radeon HD 4870 2GB		12000 Mpixels/sec
	Difference: 25056 (209%)

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 maximum amount of data (counted in MB per second) that can be transported past the external memory interface in a second. It is calculated by multiplying the bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.