Compare any two graphics cards:
Radeon HD 5970 vs Radeon HD 6990
IntroThe Radeon HD 5970 has a GPU clock speed of 725 MHz, and the 1024 MB of GDDR5 memory runs at 1000 MHz through a 256-bit bus. It also is made up of 1600 SPUs, 160 TAUs, and 64 ROPs.
Compare all that to the Radeon HD 6990, which uses a 40 nm design. AMD has clocked the core frequency at 830 MHz. The GDDR5 RAM is set to run at a speed of 1250 MHz on this specific card. It features 1536 SPUs along with 96 TAUs and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6990 is 25% quicker than the Radeon HD 5970 in general, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 5970 will be quite a bit (approximately 46%) better at AF than the Radeon HD 6990. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 5970 is a better choice, by far. (explain)
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.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Bandwidth is the max amount of data (measured in MB per second) that can be transported past the external memory interface in a second. It is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, 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 texture map elements (texels) that can be applied per second. This is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the video card will be at handling 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 that the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines 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 fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.