Compare any two graphics cards:
GeForce 820M vs GeForce 8800 GTS (G80) 320MB
IntroThe GeForce 820M features a GPU clock speed of 719 MHz, and the 2048 MB of DDR3 memory is set to run at 1000 MHz through a 64-bit bus. It also is made up of 96 SPUs, 16 Texture Address Units, and 4 ROPs.
Compare those specs to the GeForce 8800 GTS (G80) 320MB, which makes use of a 90 nm design. nVidia has clocked the core frequency at 513 MHz. The GDDR3 RAM is set to run at a frequency of 792 MHz on this card. It features 96 SPUs along with 48 TAUs and 20 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the GeForce 8800 GTS (G80) 320MB should in theory be a lot better than the GeForce 820M in general. (explain)
Texel RateThe GeForce 8800 GTS (G80) 320MB will be quite a bit (approximately 114%) faster with regards to AF than the GeForce 820M. (explain)
Pixel RateIf using high levels of AA is important to you, then the GeForce 8800 GTS (G80) 320MB 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: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be transported across the external memory interface in one second. It is calculated by multiplying the interface width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This is calculated 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 handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.