Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 4890 2GB
IntroThe GeForce GTX 650 comes with clock speeds of 1058 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 RAM. It features 384 SPUs as well as 32 Texture Address Units and 16 Rasterization Operator Units.
Compare those specifications to the Radeon HD 4890 2GB, which comes with clock speeds of 1000 MHz on the GPU, and 975 MHz on the 2048 MB of GDDR5 RAM. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 4890 2GB is 56% faster than the GeForce GTX 650 in general, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 4890 2GB is a small bit (approximately 18%) faster with regards to texture filtering than the GeForce GTX 650. (explain)
Pixel RateThe GeForce GTX 650 is a little bit (approximately 6%) more effective at AA than the Radeon HD 4890 2GB, and should be 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 maximum amount of data (counted in MB per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the interface width by its memory speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster 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 processed per second. This figure is calculated by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, 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 most pixels that the graphics card can possibly record to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.