GeForce GTX 480 vs Radeon HD 4890 1GB

Intro

Compare all that to the Radeon HD 4890 1GB, which features clock speeds of 1000 MHz on the GPU, and 975 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4890 1GB		190 Watts
GeForce GTX 480		250 Watts
	Difference: 60 Watts (32%)

Memory Bandwidth

Theoretically, the GeForce GTX 480 should be a lot faster than the Radeon HD 4890 1GB in general. (explain)

GeForce GTX 480		177408 MB/sec
Radeon HD 4890 1GB		124800 MB/sec
	Difference: 52608 (42%)

Texel Rate

The GeForce GTX 480 will be a small bit (more or less 5%) more effective at anisotropic filtering than the Radeon HD 4890 1GB. (explain)

GeForce GTX 480		42000 Mtexels/sec
Radeon HD 4890 1GB		40000 Mtexels/sec
	Difference: 2000 (5%)

Pixel Rate

The GeForce GTX 480 should be a lot (more or less 110%) better at AA than the Radeon HD 4890 1GB, and will be able to handle higher screen resolutions while still performing well. (explain)

GeForce GTX 480		33600 Mpixels/sec
Radeon HD 4890 1GB		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 max amount of data (counted in MB per second) that can be moved past the external memory interface in one second. It's worked out by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher 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 are processed in one second. This figure is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the clock 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 fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.