GeForce GTS 450 1GB vs Radeon HD 4890 1GB

Intro

Compare that to the Radeon HD 4890 1GB, which has a core clock frequency of 1000 MHz and a GDDR5 memory speed of 975 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTS 450 1GB		106 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 84 Watts (79%)

Memory Bandwidth

In theory, the Radeon HD 4890 1GB should perform much faster than the GeForce GTS 450 1GB overall. (explain)

Radeon HD 4890 1GB		124800 MB/sec
GeForce GTS 450 1GB		57728 MB/sec
	Difference: 67072 (116%)

Texel Rate

The Radeon HD 4890 1GB is much (approximately 60%) better at texture filtering than the GeForce GTS 450 1GB. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
GeForce GTS 450 1GB		25056 Mtexels/sec
	Difference: 14944 (60%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 4890 1GB is superior to the GeForce GTS 450 1GB, by far. (explain)

Radeon HD 4890 1GB		16000 Mpixels/sec
GeForce GTS 450 1GB		12528 Mpixels/sec
	Difference: 3472 (28%)

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 (in units of megabytes per second) that can be moved over the external memory interface within a second. The number is worked out by multiplying the card's interface 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 card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

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