GeForce GTX 580 vs Radeon HD 4890 2GB

Intro

Compare those specifications to the Radeon HD 4890 2GB, which has a clock speed of 1000 MHz and a GDDR5 memory frequency of 975 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 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4890 2GB		190 Watts
GeForce GTX 580		244 Watts
	Difference: 54 Watts (28%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 580 is 54% quicker than the Radeon HD 4890 2GB in general, due to its greater bandwidth. (explain)

GeForce GTX 580		192384 MB/sec
Radeon HD 4890 2GB		124800 MB/sec
	Difference: 67584 (54%)

Texel Rate

The GeForce GTX 580 should be quite a bit (more or less 24%) more effective at AF than the Radeon HD 4890 2GB. (explain)

GeForce GTX 580		49408 Mtexels/sec
Radeon HD 4890 2GB		40000 Mtexels/sec
	Difference: 9408 (24%)

Pixel Rate

The GeForce GTX 580 should be much (about 132%) better at anti-aliasing than the Radeon HD 4890 2GB, and also should be capable of handling higher resolutions more effectively. (explain)

GeForce GTX 580		37056 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 21056 (132%)

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 max amount of information (counted in MB per second) that can be transferred across the external memory interface in one second. It is calculated by multiplying the bus width by its memory clock speed. If it uses DDR type RAM, the result should 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, High Dynamic Range and high resolutions.

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