Compare any two graphics cards:
GeForce 9800 GT 1GB vs GeForce 9800 GT 512MB
IntroThe GeForce 9800 GT 1GB features core speeds of 600 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR3 memory. It features 112 SPUs as well as 56 TAUs and 16 ROPs.
Compare those specifications to the GeForce 9800 GT 512MB, which features a clock speed of 600 MHz and a GDDR3 memory frequency of 900 MHz. It also uses a 256-bit memory bus, and uses a 65/55 nm design. It is comprised of 112 SPUs, 56 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have the exact same bandwidth, so in theory they should have the same performance. (explain)
Texel RateBoth cards have the exact same texel fill rate, so in theory they should perform equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have the exact same pixel rate, so in theory they should perform equally good at at anti-aliasing, and be capable of handling the same resolutions. (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 transferred across the external memory interface in a second. It is calculated by multiplying the bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the core speed of the card. 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 lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.