Compare any two graphics cards:
GeForce 825M vs GeForce 8500 GT
IntroThe GeForce 825M features a GPU core speed of 850 MHz, and the 2048 MB of DDR3 RAM runs at 900 MHz through a 64-bit bus. It also is made up of 384 Stream Processors, 16 TAUs, and 8 ROPs.
Compare all of that to the GeForce 8500 GT, which makes use of a 80 nm design. nVidia has clocked the core frequency at 450 MHz. The DDR2 memory is set to run at a speed of 400 MHz on this card. It features 16 SPUs along with 8 Texture Address Units and 4 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce 825M should be 13% faster than the GeForce 8500 GT in general, due to its greater data rate. (explain)
Texel RateThe GeForce 825M should be quite a bit (more or less 278%) faster with regards to anisotropic filtering than the GeForce 8500 GT. (explain)
Pixel RateThe GeForce 825M is much (more or less 278%) faster with regards to FSAA than the GeForce 8500 GT, and will be capable of handling higher resolutions without slowing down too much. (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 largest amount of information (measured in MB per second) that can be transferred across the external memory interface in one second. It is worked out by multiplying the card's bus width by its memory speed. If it uses DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per 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 handling 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 could possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.