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 set the core frequency at 513 MHz. The GDDR3 memory is set to run at a speed of 792 MHz on this card. It features 96 SPUs as well as 48 Texture Address Units and 20 ROPs.
Compare all that to the Radeon HD 4650 1GB, which features a core clock frequency of 600 MHz and a GDDR3 memory frequency of 700 MHz. It also uses a 128-bit memory bus, and makes use of a 55 nm design. It features 320(64x5) SPUs, 32 Texture Address Units, and 8 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce 8800 GTS (G80) 640MB will be 183% quicker than the Radeon HD 4650 1GB in general, due to its greater data rate. (explain)
Texel RateThe GeForce 8800 GTS (G80) 640MB will be much (approximately 28%) more effective at texture filtering than the Radeon HD 4650 1GB. (explain)
Pixel RateIf running with high levels of AA is important to you, then the GeForce 8800 GTS (G80) 640MB is superior to the Radeon HD 4650 1GB, by a large margin. (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 maximum amount of data (measured in megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster 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 are applied per second. This figure is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, 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 maximum amount of pixels the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.