GeForce 8800 GTS (G80) 640MB vs Radeon HD 4850 X2 512MB

Intro

Compare those specs to the Radeon HD 4850 X2 512MB, which features core clock speeds of 625 MHz on the GPU, and 993 MHz on the 512 MB of GDDR3 memory. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 GTS (G80) 640MB		143 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 107 Watts (75%)

Memory Bandwidth

In theory, the Radeon HD 4850 X2 512MB should be quite a bit faster than the GeForce 8800 GTS (G80) 640MB overall. (explain)

Radeon HD 4850 X2 512MB		127104 MB/sec
GeForce 8800 GTS (G80) 640MB		63360 MB/sec
	Difference: 63744 (101%)

Texel Rate

The Radeon HD 4850 X2 512MB is quite a bit (approximately 103%) more effective at anisotropic filtering than the GeForce 8800 GTS (G80) 640MB. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
	Difference: 25376 (103%)

Pixel Rate

The Radeon HD 4850 X2 512MB is a lot (more or less 95%) faster with regards to anti-aliasing than the GeForce 8800 GTS (G80) 640MB, and also should be able to handle higher resolutions better. (explain)

Radeon HD 4850 X2 512MB		20000 Mpixels/sec
GeForce 8800 GTS (G80) 640MB		10260 Mpixels/sec
	Difference: 9740 (95%)

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 largest amount of data (counted in MB per second) that can be transferred past the external memory interface in a second. It is calculated by multiplying the interface width by its memory clock speed. If it uses DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total texture units by the core clock 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 processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour 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 output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.