Compare any two graphics cards:
Radeon HD 5970 vs Radeon HD 6990
IntroThe Radeon HD 5970 features a GPU core clock speed of 725 MHz, and the 1024 MB of GDDR5 RAM runs at 1000 MHz through a 256-bit bus. It also features 1600 SPUs, 160 TAUs, and 64 ROPs.
Compare all of that to the Radeon HD 6990, which uses a 40 nm design. AMD has clocked the core speed at 830 MHz. The GDDR5 RAM runs at a speed of 1250 MHz on this particular model. It features 1536 SPUs along with 96 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6990 should perform quite a bit faster than the Radeon HD 5970 overall. (explain)
Texel RateThe Radeon HD 5970 is much (about 46%) better at anisotropic filtering than the Radeon HD 6990. (explain)
Pixel RateThe Radeon HD 5970 should be much (about 75%) better at AA than the Radeon HD 6990, and also able to handle higher resolutions without losing too much performance. (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: Memory bandwidth is the max amount of information (counted in MB per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the card's 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 are processed in one second. This number is worked out by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.