GeForce GTX 580 3GB vs Radeon HD 4870 X2

Intro

Compare all of that to the Radeon HD 4870 X2, which uses a 55 nm design. ATi has clocked the core frequency at 750 MHz. The GDDR5 memory runs at a frequency of 900 MHz on this specific model. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 580 3GB		244 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 106 Watts (43%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 X2 should be 20% quicker than the GeForce GTX 580 3GB in general, due to its greater data rate. (explain)

Radeon HD 4870 X2		230400 MB/sec
GeForce GTX 580 3GB		192384 MB/sec
	Difference: 38016 (20%)

Texel Rate

The Radeon HD 4870 X2 will be a lot (more or less 21%) faster with regards to texture filtering than the GeForce GTX 580 3GB. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
GeForce GTX 580 3GB		49408 Mtexels/sec
	Difference: 10592 (21%)

Pixel Rate

If running with a high resolution is important to you, then the GeForce GTX 580 3GB is the winner, by far. (explain)

GeForce GTX 580 3GB		37056 Mpixels/sec
Radeon HD 4870 X2		24000 Mpixels/sec
	Difference: 13056 (54%)

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: Bandwidth is the max amount of information (measured in megabytes per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.