Compare any two graphics cards:
GeForce GTX 280 vs Radeon HD 7950
IntroThe GeForce GTX 280 has clock speeds of 602 MHz on the GPU, and 1107 MHz on the 1024 MB of GDDR3 RAM. It features 240 SPUs along with 80 Texture Address Units and 32 ROPs.
Compare those specs to the Radeon HD 7950, which has a core clock frequency of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also uses a 384-bit memory bus, and makes use of a 28 nm design. It features 1792 SPUs, 112 Texture Address Units, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7950 should in theory be a lot superior to the GeForce GTX 280 overall. (explain)
Texel RateThe Radeon HD 7950 is quite a bit (about 86%) better at AF than the GeForce GTX 280. (explain)
Pixel RateThe Radeon HD 7950 will be quite a bit (about 33%) faster with regards to AA than the GeForce GTX 280, and also capable of handling higher screen resolutions without slowing down too much. (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 information (in units of megabytes per second) that can be transferred over the external memory interface in one second. The number is worked out by multiplying the bus width by its memory clock speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines 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 fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.