Compare any two graphics cards:
GeForce GTX 285 1GB vs Radeon HD 4890 1GB
IntroThe GeForce GTX 285 1GB makes use of a 55 nm design. nVidia has set the core frequency at 648 MHz. The GDDR3 RAM works at a speed of 1242 MHz on this particular model. It features 240 SPUs as well as 80 Texture Address Units and 32 ROPs.
Compare those specs to the Radeon HD 4890 1GB, which features a clock speed of 1000 MHz and a GDDR5 memory frequency of 975 MHz. It also uses a 256-bit memory bus, and uses a 55 nm design. It features 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the GeForce GTX 285 1GB should in theory be much superior to the Radeon HD 4890 1GB overall. (explain)
Texel RateThe GeForce GTX 285 1GB is quite a bit (about 30%) faster with regards to AF than the Radeon HD 4890 1GB. (explain)
Pixel RateIf running with a high resolution is important to you, then the GeForce GTX 285 1GB is a better choice, and very much so. (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 (measured in MB per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the card's 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 rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.