GeForce GTX 480 vs Radeon HD 4890 2GB

Intro

Compare all of that to the Radeon HD 4890 2GB, which features a clock speed of 1000 MHz and a GDDR5 memory speed of 975 MHz. It also makes use of a 256-bit bus, and uses a 55 nm design. It is made up of 800(160x5) SPUs, 40 TAUs, 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 480		250 Watts
	Difference: 60 Watts (32%)

Memory Bandwidth

The GeForce GTX 480 should in theory perform quite a bit faster than the Radeon HD 4890 2GB in general. (explain)

GeForce GTX 480		177408 MB/sec
Radeon HD 4890 2GB		124800 MB/sec
	Difference: 52608 (42%)

Texel Rate

The GeForce GTX 480 will be just a bit (approximately 5%) more effective at texture filtering than the Radeon HD 4890 2GB. (explain)

GeForce GTX 480		42000 Mtexels/sec
Radeon HD 4890 2GB		40000 Mtexels/sec
	Difference: 2000 (5%)

Pixel Rate

The GeForce GTX 480 is much (about 110%) more effective at anti-aliasing than the Radeon HD 4890 2GB, and capable of handling higher resolutions while still performing well. (explain)

GeForce GTX 480		33600 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 17600 (110%)

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: Bandwidth is the max amount of data (in units of megabytes per second) that can be moved over the external memory interface in one second. The number is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, 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 texture map elements (texels) that can be processed per second. This is worked out by multiplying the total texture units by the core 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 processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated 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 filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.