Compare any two graphics cards:
GeForce GTX 260 vs Radeon HD 4890 1GB
IntroThe GeForce GTX 260 comes with a GPU clock speed of 576 MHz, and the 896 MB of GDDR3 RAM runs at 999 MHz through a 448-bit bus. It also is comprised of 192 SPUs, 64 TAUs, and 28 Raster Operation Units.
Compare those specs to the Radeon HD 4890 1GB, which has core speeds of 1000 MHz on the GPU, and 975 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 4890 1GB, in theory, should perform a little bit faster than the GeForce GTX 260 overall. (explain)
Texel RateThe Radeon HD 4890 1GB is a small bit (about 9%) faster with regards to AF than the GeForce GTX 260. (explain)
Pixel RateThe GeForce GTX 260 should be a bit (approximately 1%) faster with regards to AA than the Radeon HD 4890 1GB, and should be able to handle 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: Memory bandwidth is the largest amount of data (in units of MB per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one 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. Pixel rate is calculated by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.