Radeon HD 5870 vs Radeon HD 6990

Intro

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

(No game benchmarks for this combination yet.)

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

Theoretically speaking, the Radeon HD 6990 should be quite a bit faster than the Radeon HD 5870 in general. (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 (more or less 134%) faster with regards to anisotropic filtering 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 is a lot (about 95%) more effective at anti-aliasing than the Radeon HD 5870, and also will be able to handle higher screen resolutions more effectively. (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: Bandwidth is the largest amount of information (measured in MB per second) that can be transported over the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory speed. In the case of DDR type RAM, it 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 anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total amount of texture units by the core clock 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 processed in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video 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 ROPs by the the core clock speed. 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 rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.