Compare any two graphics cards:
GeForce 9800 GTX vs GeForce GTS 250 1GB
IntroThe GeForce 9800 GTX comes with a GPU core clock speed of 675 MHz, and the 512 MB of GDDR3 memory is set to run at 1100 MHz through a 256-bit bus. It also is comprised of 128 SPUs, 64 TAUs, and 16 Raster Operation Units.
Compare that to the GeForce GTS 250 1GB, which has GPU clock speed of 738 MHz, and 1024 MB of GDDR3 RAM set to run at 1100 MHz through a 256-bit bus. It also is made up of 128 SPUs, 64 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same bandwidth, so in theory they should perform the same. (explain)
Texel RateThe GeForce GTS 250 1GB will be just a bit (more or less 9%) faster with regards to AF than the GeForce 9800 GTX. (explain)
Pixel RateThe GeForce GTS 250 1GB should be a small bit (more or less 9%) better at anti-aliasing than the GeForce 9800 GTX, and will be able to handle higher screen 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: Memory bandwidth is the maximum amount of information (in units of MB per second) that can be transported past the external memory interface in one second. It's calculated by multiplying the interface width by its memory clock speed. If the card has DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better 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 number of texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.