Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 7790
IntroThe Radeon HD 6870 features a GPU core clock speed of 900 MHz, and the 1024 MB of GDDR5 memory runs at 1050 MHz through a 256-bit bus. It also is comprised of 1120 Stream Processors, 56 TAUs, and 32 ROPs.
Compare all of that to the Radeon HD 7790, which has GPU clock speed of 1000 MHz, and 1024 MB of GDDR5 RAM running at 1500 MHz through a 128-bit bus. It also is comprised of 896 SPUs, 56 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 6870 should theoretically be much superior to the Radeon HD 7790 overall. (explain)
Texel RateThe Radeon HD 7790 will be a little bit (approximately 11%) more effective at texture filtering than the Radeon HD 6870. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 6870 is superior to the Radeon HD 7790, 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: Memory bandwidth is the max amount of data (in units of MB per second) that can be transferred across the external memory interface in one second. The number is calculated by multiplying the bus width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total amount of 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 in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.