GeForce 9800 GX2 vs Radeon HD 4870 X2

Intro

Compare those specifications to the Radeon HD 4870 X2, which comes with GPU core speed of 750 MHz, and 1024 MB of GDDR5 RAM running at 900 MHz through a 256-bit bus. It also is comprised of 800(160x5) Stream Processors, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 9800 GX2		197 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 153 Watts (78%)

Memory Bandwidth

Performance-wise, the Radeon HD 4870 X2 should theoretically be quite a bit better than the GeForce 9800 GX2 in general. (explain)

Radeon HD 4870 X2		230400 MB/sec
GeForce 9800 GX2		128000 MB/sec
	Difference: 102400 (80%)

Texel Rate

The GeForce 9800 GX2 is a lot (about 28%) more effective at anisotropic filtering than the Radeon HD 4870 X2. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 4870 X2		60000 Mtexels/sec
	Difference: 16800 (28%)

Pixel Rate

The Radeon HD 4870 X2 should be much (about 25%) faster with regards to AA than the GeForce 9800 GX2, and should be capable of handling higher resolutions better. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
GeForce 9800 GX2		19200 Mpixels/sec
	Difference: 4800 (25%)

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 transported over the external memory interface within a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, the result should 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 anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is worked out by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the card's 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 quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.