GeForce GTS 450 vs Radeon HD 3870 X2 1GB

Intro

Compare that to the Radeon HD 3870 X2 1GB, which comes with a core clock frequency of 825 MHz and a GDDR4 memory frequency of 1126 MHz. It also makes use of a 256-bit memory bus, and uses a 55 nm design. It is made up of 320(64x5) SPUs, 16 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

As far as performance goes, the Radeon HD 3870 X2 1GB should theoretically be a lot superior to the GeForce GTS 450 overall. (explain)

Radeon HD 3870 X2 1GB		144128 MB/sec
GeForce GTS 450		57728 MB/sec
	Difference: 86400 (150%)

Texel Rate

The Radeon HD 3870 X2 1GB will be a bit (approximately 5%) better at anisotropic filtering than the GeForce GTS 450. (explain)

Radeon HD 3870 X2 1GB		26400 Mtexels/sec
GeForce GTS 450		25056 Mtexels/sec
	Difference: 1344 (5%)

Pixel Rate

The Radeon HD 3870 X2 1GB is a lot (about 111%) more effective at full screen anti-aliasing than the GeForce GTS 450, and able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 3870 X2 1GB		26400 Mpixels/sec
GeForce GTS 450		12528 Mpixels/sec
	Difference: 13872 (111%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of information (measured in megabytes per second) that can be transferred across the external memory interface in one second. It's calculated by multiplying the interface width by its memory clock speed. If it uses DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics 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 the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.