Compare any two graphics cards:
Radeon HD 7870 vs Radeon HD 7970
IntroThe Radeon HD 7870 makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 RAM runs at a speed of 1200 MHz on this particular card. It features 1280 SPUs along with 80 TAUs and 32 ROPs.
Compare those specs to the Radeon HD 7970, which has a core clock speed of 925 MHz and a GDDR5 memory frequency of 1375 MHz. It also features a 384-bit bus, and uses a 28 nm design. It is made up of 2048 SPUs, 128 Texture Address Units, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7970 will be 72% quicker than the Radeon HD 7870 overall, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 7970 is quite a bit (approximately 48%) faster with regards to AF than the Radeon HD 7870. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 7870 is a better choice, though only just barely. (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 largest amount of data (in units of MB per second) that can be moved across the external memory interface in a second. The number is calculated by multiplying the bus width by the speed of its memory. If the card has DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This number is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the video card will be at 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 can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the card's clock speed. 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 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 get to the max fill rate.