Radeon HD 5870 vs Radeon HD 6990

Intro

Compare that to the Radeon HD 6990, which features a clock speed of 830 MHz and a GDDR5 memory speed of 1250 MHz. It also uses a 256-bit memory bus, and makes use of a 40 nm design. It is made up of 1536 SPUs, 96 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5870		188 Watts
Radeon HD 6990		375 Watts
	Difference: 187 Watts (99%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6990 should theoretically be quite a bit better than the Radeon HD 5870 overall. (explain)

Radeon HD 6990		320000 MB/sec
Radeon HD 5870		153600 MB/sec
	Difference: 166400 (108%)

Texel Rate

The Radeon HD 6990 will be a lot (approximately 134%) better at AF than the Radeon HD 5870. (explain)

Radeon HD 6990		159360 Mtexels/sec
Radeon HD 5870		68000 Mtexels/sec
	Difference: 91360 (134%)

Pixel Rate

The Radeon HD 6990 should be quite a bit (more or less 95%) better at AA than the Radeon HD 5870, and also should be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 6990		53120 Mpixels/sec
Radeon HD 5870		27200 Mpixels/sec
	Difference: 25920 (95%)

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: Memory bandwidth is the largest amount of information (in units of MB per second) that can be transported over the external memory interface in one second. It is worked out by multiplying the bus width by its memory speed. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster 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 can be applied in one second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to its local memory in one 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 - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.