Compare any two graphics cards:
GeForce 8800 GTS (G80) 640MB vs Radeon HD 4650 1GB
IntroThe GeForce 8800 GTS (G80) 640MB uses a 90 nm design. nVidia has clocked the core frequency at 513 MHz. The GDDR3 memory works at a speed of 792 MHz on this card. It features 96 SPUs as well as 48 Texture Address Units and 20 ROPs.
Compare those specs to the Radeon HD 4650 1GB, which has a core clock speed of 600 MHz and a GDDR3 memory frequency of 700 MHz. It also uses a 128-bit bus, and makes use of a 55 nm design. It is comprised of 320(64x5) SPUs, 32 Texture Address Units, and 8 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce 8800 GTS (G80) 640MB will be 183% faster than the Radeon HD 4650 1GB overall, because of its greater bandwidth. (explain)
Texel RateThe GeForce 8800 GTS (G80) 640MB is quite a bit (more or less 28%) more effective at texture filtering than the Radeon HD 4650 1GB. (explain)
Pixel RateThe GeForce 8800 GTS (G80) 640MB will be much (more or less 114%) faster with regards to FSAA than the Radeon HD 4650 1GB, and also should be able to handle 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: Memory bandwidth is the max amount of information (counted in MB per second) that can be transferred past the external memory interface within a second. It is calculated by multiplying the card's interface width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better 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 amount of texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total texture units by the core clock 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 applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.