Compare any two graphics cards:
GeForce 840M vs GeForce 9400 GT 256MB
IntroThe GeForce 840M comes with a clock speed of 1029 MHz and a DDR3 memory frequency of 1000 MHz. It also uses a 64-bit bus, and makes use of a 28 nm design. It is comprised of 384 SPUs, 24 Texture Address Units, and 8 Raster Operation Units.
Compare those specs to the GeForce 9400 GT 256MB, which makes use of a 65 nm design. nVidia has clocked the core speed at 550 MHz. The GDDR2 RAM works at a speed of 400 MHz on this specific card. It features 16 SPUs as well as 8 Texture Address Units and 4 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the GeForce 840M should perform quite a bit faster than the GeForce 9400 GT 256MB overall. (explain)
Texel RateThe GeForce 840M will be a lot (more or less 461%) faster with regards to texture filtering than the GeForce 9400 GT 256MB. (explain)
Pixel RateThe GeForce 840M should be quite a bit (more or less 274%) more effective at anti-aliasing than the GeForce 9400 GT 256MB, and will be capable of handling higher resolutions better. (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 (measured in MB per second) that can be transported across the external memory interface in one second. The number is calculated by multiplying the interface width by the speed of its memory. If the card has DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better 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 in one second. This figure is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.