Compare any two graphics cards:
GeForce 9800 GTX vs GeForce GTS 250 1GB
IntroThe GeForce 9800 GTX comes with clock speeds of 675 MHz on the GPU, and 1100 MHz on the 512 MB of GDDR3 memory. It features 128 SPUs as well as 64 TAUs and 16 ROPs.
Compare all of that to the GeForce GTS 250 1GB, which makes use of a 65/55 nm design. nVidia has set the core frequency at 738 MHz. The GDDR3 RAM is set to run at a frequency of 1100 MHz on this card. It features 128 SPUs as well as 64 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same memory bandwidth, so theoretically they should perform exactly the same. (explain)
Texel RateThe GeForce GTS 250 1GB will be a bit (approximately 9%) better at AF than the GeForce 9800 GTX. (explain)
Pixel RateIf using high levels of AA is important to you, then the GeForce GTS 250 1GB is the winner, but not by far. (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 data (in units of megabytes per second) that can be transferred over the external memory interface within a second. The number is calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster 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 can be applied per second. This is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the 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 amount of pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.