GeForce 9800 GX2 vs Radeon HD 7870

Intro

Compare those specs to the Radeon HD 7870, which features a clock frequency of 1000 MHz and a GDDR5 memory speed of 1200 MHz. It also uses a 256-bit bus, and makes use of a 28 nm design. It features 1280 SPUs, 80 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7870		175 Watts
GeForce 9800 GX2		197 Watts
	Difference: 22 Watts (13%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7870 should in theory be a bit superior to the GeForce 9800 GX2 overall. (explain)

Radeon HD 7870		153600 MB/sec
GeForce 9800 GX2		128000 MB/sec
	Difference: 25600 (20%)

Texel Rate

The Radeon HD 7870 will be just a bit (approximately 4%) faster with regards to texture filtering than the GeForce 9800 GX2. (explain)

Radeon HD 7870		80000 Mtexels/sec
GeForce 9800 GX2		76800 Mtexels/sec
	Difference: 3200 (4%)

Pixel Rate

The Radeon HD 7870 is quite a bit (more or less 67%) better at AA than the GeForce 9800 GX2, and capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 7870		32000 Mpixels/sec
GeForce 9800 GX2		19200 Mpixels/sec
	Difference: 12800 (67%)

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 (measured in megabytes per second) that can be transferred past the external memory interface in one second. It's calculated by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better 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 can be processed in one second. This number is worked out by multiplying the total amount of texture units 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 in one second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel 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 potential to get to the maximum fill rate.