Radeon HD 5870 vs Radeon HD 7870

Intro

Compare all of that to the Radeon HD 7870, which comes with core speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1280 SPUs as well as 80 TAUs and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7870		175 Watts
Radeon HD 5870		188 Watts
	Difference: 13 Watts (7%)

Memory Bandwidth

Both cards have the exact same bandwidth, so theoretically they should have identical performance. (explain)

Texel Rate

The Radeon HD 7870 will be a bit (about 18%) better at AF than the Radeon HD 5870. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon HD 5870		68000 Mtexels/sec
	Difference: 12000 (18%)

Pixel Rate

The Radeon HD 7870 will be a small bit (approximately 18%) faster with regards to FSAA than the Radeon HD 5870, and able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon HD 5870		27200 Mpixels/sec
	Difference: 4800 (18%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the largest amount of information (counted in MB per second) that can be transported over the external memory interface within a second. It is calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the 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 amount of texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.