GeForce GTS 450 vs Radeon HD 4890 2GB

Intro

Compare those specs to the Radeon HD 4890 2GB, which features a core clock speed of 1000 MHz and a GDDR5 memory frequency of 975 MHz. It also uses a 256-bit memory bus, and uses a 55 nm design. It is made up 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		106 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 84 Watts (79%)

Memory Bandwidth

Performance-wise, the Radeon HD 4890 2GB should in theory be much better than the GeForce GTS 450 in general. (explain)

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

Texel Rate

The Radeon HD 4890 2GB should be quite a bit (about 60%) more effective at texture filtering than the GeForce GTS 450. (explain)

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

Pixel Rate

The Radeon HD 4890 2GB will be much (approximately 28%) more effective at FSAA than the GeForce GTS 450, and also should be able to handle higher resolutions while still performing well. (explain)

Radeon HD 4890 2GB		16000 Mpixels/sec
GeForce GTS 450		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 maximum amount of data (counted in megabytes per second) that can be transferred past the external memory interface within a second. It is worked out by multiplying the bus width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, 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 the video card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.