GeForce GTX 480 vs Radeon HD 4890 2GB

Intro

Compare that to the Radeon HD 4890 2GB, which comes with clock speeds of 1000 MHz on the GPU, and 975 MHz on the 2048 MB of GDDR5 memory. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.

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 theoretically perform a lot faster than the Radeon HD 4890 2GB overall. (explain)

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

Texel Rate

The GeForce GTX 480 should be a bit (approximately 5%) better 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 will be a lot (about 110%) more effective at FSAA than the Radeon HD 4890 2GB, and also able to handle higher resolutions more effectively. (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: Memory bandwidth is the maximum amount of information (measured in megabytes per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the bus width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.