Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 4890 2GB
IntroThe GeForce GTX 650 has core clock speeds of 1058 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 memory. It features 384 SPUs as well as 32 TAUs and 16 Rasterization Operator Units.
Compare all of that to the Radeon HD 4890 2GB, which features a core clock frequency of 1000 MHz and a GDDR5 memory frequency of 975 MHz. It also features a 256-bit memory bus, and uses a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 4890 2GB will be 56% quicker than the GeForce GTX 650 overall, because of its greater data rate. (explain)
Texel RateThe Radeon HD 4890 2GB will be just a bit (about 18%) faster with regards to AF than the GeForce GTX 650. (explain)
Pixel RateThe GeForce GTX 650 will be a bit (about 6%) more effective at FSAA than the Radeon HD 4890 2GB, and also will be capable of handling higher resolutions more effectively. (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 (counted in MB per second) that can be moved past the external memory interface within a second. It's calculated by multiplying the bus width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. 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 processed per second. This is calculated by multiplying the total number of texture units 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 processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.