GeForce 9800 GX2 vs Radeon HD 4870 1GB

Intro

Compare that to the Radeon HD 4870 1GB, which comes with clock speeds of 750 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 1GB		150 Watts
GeForce 9800 GX2		197 Watts
	Difference: 47 Watts (31%)

Memory Bandwidth

Performance-wise, the GeForce 9800 GX2 should in theory be just a bit better than the Radeon HD 4870 1GB in general. (explain)

GeForce 9800 GX2		128000 MB/sec
Radeon HD 4870 1GB		115200 MB/sec
	Difference: 12800 (11%)

Texel Rate

The GeForce 9800 GX2 should be a lot (about 156%) faster with regards to anisotropic filtering than the Radeon HD 4870 1GB. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 4870 1GB		30000 Mtexels/sec
	Difference: 46800 (156%)

Pixel Rate

The GeForce 9800 GX2 is much (approximately 60%) better at anti-aliasing than the Radeon HD 4870 1GB, and also capable of handling higher screen resolutions more effectively. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
Radeon HD 4870 1GB		12000 Mpixels/sec
	Difference: 7200 (60%)

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 max amount of information (measured in MB per second) that can be moved across the external memory interface within a second. It's worked out by multiplying the bus width by the speed of its memory. If the card has DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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