Compare any two graphics cards:
GeForce 8800 GTS (G92) vs GeForce GT 640 DDR3
IntroThe GeForce 8800 GTS (G92) features a clock frequency of 650 MHz and a GDDR3 memory frequency of 970 MHz. It also uses a 256-bit bus, and uses a 65 nm design. It is comprised of 128 SPUs, 64 Texture Address Units, and 16 ROPs.
Compare those specifications to the GeForce GT 640 DDR3, which comes with clock speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 memory. It features 384 SPUs as well as 32 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the GeForce 8800 GTS (G92) should theoretically be a bit better than the GeForce GT 640 DDR3 in general. (explain)
Texel RateThe GeForce 8800 GTS (G92) will be quite a bit (more or less 44%) better at AF than the GeForce GT 640 DDR3. (explain)
Pixel RateThe GeForce GT 640 DDR3 should be much (about 38%) faster with regards to FSAA than the GeForce 8800 GTS (G92), and also able to handle higher screen resolutions while still performing well. (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 (counted in MB per second) that can be moved over the external memory interface in a second. It is calculated by multiplying the bus width by its memory speed. In the case of DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the better 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 are applied per second. This figure 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 processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines 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 output rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.