GeForce GTS 450 1GB vs Radeon HD 4890 2GB

Intro

Compare all that to the Radeon HD 4890 2GB, which has a core clock frequency of 1000 MHz and a GDDR5 memory frequency of 975 MHz. It also makes use of a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, 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 2GB		190 Watts
	Difference: 84 Watts (79%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4890 2GB should theoretically be quite a bit superior to the GeForce GTS 450 1GB overall. (explain)

Radeon HD 4890 2GB		124800 MB/sec
GeForce GTS 450 1GB		57728 MB/sec
	Difference: 67072 (116%)

Texel Rate

The Radeon HD 4890 2GB is quite a bit (approximately 60%) more effective at AF than the GeForce GTS 450 1GB. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
GeForce GTS 450 1GB		25056 Mtexels/sec
	Difference: 14944 (60%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 4890 2GB is the winner, by far. (explain)

Radeon HD 4890 2GB		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: Bandwidth is the largest amount of data (counted in MB per second) that can be moved over the external memory interface within a second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better 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 applied per second. This number is worked out by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record 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 core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.