Compare any two graphics cards:
GeForce GTS 450 vs GeForce GTS 450 1GB
IntroThe GeForce GTS 450 features a core clock frequency of 783 MHz and a GDDR5 memory frequency of 902 MHz. It also uses a 128-bit bus, and makes use of a 40 nm design. It is made up of 192 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare those specs to the GeForce GTS 450 1GB, which comes with clock speeds of 783 MHz on the GPU, and 902 MHz on the 1024 MB of GDDR5 RAM. It features 192 SPUs along with 32 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have the exact same bandwidth, so theoretically they should have the same performance. (explain)
Texel RateBoth cards have exactly the same texel fill rate, so in theory they should be equally good at at AF. (explain)
Pixel RateBoth cards have the exact same pixel fill rate, so in theory they should be equally good at at anti-aliasing, and be able to handle the same screen 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: Bandwidth is the largest amount of information (counted in megabytes per second) that can be moved over the external memory interface in a second. It is calculated by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster 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 texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, 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 maximum amount of pixels the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.