Compare any two graphics cards:
Geforce GTX 780 vs Radeon HD 7950
IntroThe Geforce GTX 780 has a GPU core clock speed of 863 MHz, and the 3072 MB of GDDR5 memory runs at 1502 MHz through a 384-bit bus. It also is made up of 2304 SPUs, 192 TAUs, and 48 Raster Operation Units.
Compare all that to the Radeon HD 7950, which features a core clock frequency of 800 MHz and a GDDR5 memory frequency of 1250 MHz. It also makes use of a 384-bit memory bus, and uses a 28 nm design. It is made up of 1792 SPUs, 112 Texture Address Units, and 32 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Geforce GTX 780 should be 20% quicker than the Radeon HD 7950 overall, because of its higher data rate. (explain)
Texel RateThe Geforce GTX 780 will be much (approximately 85%) faster with regards to AF than the Radeon HD 7950. (explain)
Pixel RateThe Geforce GTX 780 should be quite a bit (more or less 62%) better at FSAA than the Radeon HD 7950, and also 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: Memory bandwidth is the maximum amount of data (measured in MB per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the bus width by the speed of its memory. If it uses DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total texture units of the card by the core 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 processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.