Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 4890 2GB
IntroThe GeForce GTX 650 features a GPU clock speed of 1058 MHz, and the 2048 MB of GDDR5 memory runs at 1250 MHz through a 128-bit bus. It also is comprised of 384 SPUs, 32 TAUs, and 16 Raster Operation Units.
Compare all of that to the Radeon HD 4890 2GB, which uses a 55 nm design. AMD has set the core frequency at 1000 MHz. The GDDR5 RAM is set to run at a speed of 975 MHz on this model. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 4890 2GB, in theory, should be much faster than the GeForce GTX 650 in general. (explain)
Texel RateThe Radeon HD 4890 2GB is a little bit (more or less 18%) better at AF than the GeForce GTX 650. (explain)
Pixel RateThe GeForce GTX 650 should be a bit (more or less 6%) better at full screen anti-aliasing than the Radeon HD 4890 2GB, and will be able to handle higher resolutions better. (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 max amount of data (in units of megabytes per second) that can be moved past the external memory interface in one second. The number is worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR type RAM, 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 AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The better this number, the better the graphics 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 most pixels that the graphics chip can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.