Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 7790
IntroThe Radeon HD 6870 makes use of a 40 nm design. AMD has set the core frequency at 900 MHz. The GDDR5 memory works at a speed of 1050 MHz on this particular model. It features 1120 SPUs along with 56 TAUs and 32 Rasterization Operator Units.
Compare all that to the Radeon HD 7790, which has GPU core speed of 1000 MHz, and 1024 MB of GDDR5 memory running at 1500 MHz through a 128-bit bus. It also is comprised of 896 SPUs, 56 Texture Address Units, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6870, in theory, should perform quite a bit faster than the Radeon HD 7790 overall. (explain)
Texel RateThe Radeon HD 7790 should be a little bit (about 11%) faster with regards to texture filtering than the Radeon HD 6870. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 6870 is the winner, by a large margin. (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.
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 information (counted in MB per second) that can be transferred over the external memory interface in one second. The number is worked out by multiplying the interface width by the speed of its memory. In the case of DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR 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 worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, 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 the video card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.