GeForce 9800 GX2 vs Radeon HD 4870 512MB

Intro

Compare all of that to the Radeon HD 4870 512MB, which has core clock speeds of 750 MHz on the GPU, and 900 MHz on the 512 MB of GDDR5 RAM. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 512MB		150 Watts
GeForce 9800 GX2		197 Watts
	Difference: 47 Watts (31%)

Memory Bandwidth

Theoretically speaking, the GeForce 9800 GX2 should be 11% quicker than the Radeon HD 4870 512MB overall, because of its higher data rate. (explain)

GeForce 9800 GX2		128000 MB/sec
Radeon HD 4870 512MB		115200 MB/sec
	Difference: 12800 (11%)

Texel Rate

The GeForce 9800 GX2 is quite a bit (more or less 156%) more effective at anisotropic filtering than the Radeon HD 4870 512MB. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 46800 (156%)

Pixel Rate

The GeForce 9800 GX2 will be a lot (more or less 60%) faster with regards to FSAA than the Radeon HD 4870 512MB, and also should be able to handle higher screen resolutions better. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
Radeon HD 4870 512MB		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 data (in units of MB per second) that can be transferred past the external memory interface in one second. It's worked out 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 it uses DDR5, multiply by ANOTHER 2x. 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 processed per second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.