Compare any two graphics cards:
GeForce GTX 260 vs Radeon HD 4890 1GB
IntroThe GeForce GTX 260 comes with a GPU core speed of 576 MHz, and the 896 MB of GDDR3 RAM runs at 999 MHz through a 448-bit bus. It also features 192 SPUs, 64 TAUs, and 28 ROPs.
Compare all that to the Radeon HD 4890 1GB, which features clock speeds of 1000 MHz on the GPU, and 975 MHz on the 1024 MB of GDDR5 RAM. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 4890 1GB is 12% quicker than the GeForce GTX 260 in general, because of its greater data rate. (explain)
Texel RateThe Radeon HD 4890 1GB is a small bit (about 9%) more effective at anisotropic filtering than the GeForce GTX 260. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the GeForce GTX 260 is a better choice, though only just barely. (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 information (in units of MB per second) that can be transported past the external memory interface in a second. It is calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better 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 applied in one second. This number is calculated by multiplying the total amount of texture units of the card by the core 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 per second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.