Compare any two graphics cards:
GeForce 840M vs GeForce 8600 GT 512MB DDR2
IntroThe GeForce 840M has clock speeds of 1029 MHz on the GPU, and 1000 MHz on the 2048 MB of DDR3 memory. It features 384 SPUs along with 24 Texture Address Units and 8 Rasterization Operator Units.
Compare those specs to the GeForce 8600 GT 512MB DDR2, which comes with GPU clock speed of 540 MHz, and 512 MB of DDR2 RAM set to run at 400 MHz through a 128-bit bus. It also is comprised of 32 Stream Processors, 16 Texture Address Units, and 8 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the GeForce 840M should theoretically be a lot better than the GeForce 8600 GT 512MB DDR2 in general. (explain)
Texel RateThe GeForce 840M will be a lot (about 186%) better at anisotropic filtering than the GeForce 8600 GT 512MB DDR2. (explain)
Pixel RateThe GeForce 840M should be quite a bit (more or less 91%) faster with regards to AA than the GeForce 8600 GT 512MB DDR2, and also capable of handling higher 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 max amount of information (counted in MB per second) that can be transferred past the external memory interface in a second. It is calculated by multiplying the interface width by its memory speed. In the case of DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's 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 texture map elements (texels) that are applied per second. This is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.