Compare any two graphics cards:
Radeon HD 7870 vs Radeon HD 7950 3GB
IntroThe Radeon HD 7870 makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 RAM runs at a frequency of 1200 MHz on this model. It features 1280 SPUs as well as 80 TAUs and 32 Rasterization Operator Units.
Compare all that to the Radeon HD 7950 3GB, which features core clock speeds of 800 MHz on the GPU, and 1250 MHz on the 3072 MB of GDDR5 RAM. It features 1792 SPUs along with 112 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7950 3GB will be 56% quicker than the Radeon HD 7870 overall, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 7950 3GB should be a little bit (more or less 12%) faster with regards to anisotropic filtering than the Radeon HD 7870. (explain)
Pixel RateThe Radeon HD 7870 is much (more or less 25%) better at AA than the Radeon HD 7950 3GB, and will be 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.
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 (measured in megabytes per second) that can be moved past the external memory interface in one second. It's worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the video card will be at 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 graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs 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 output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.