Compare any two graphics cards:
Radeon HD 4670 1GB vs Radeon HD 4670 512MB
IntroThe Radeon HD 4670 1GB features a GPU core speed of 750 MHz, and the 1024 MB of GDDR4/GDDR3/DDR3/DDR2 RAM runs at 1100 MHz through a 128-bit bus. It also features 320(64x5) Stream Processors, 32 Texture Address Units, and 8 Raster Operation Units.
Compare those specifications to the Radeon HD 4670 512MB, which features clock speeds of 750 MHz on the GPU, and 1000 MHz on the 512 MB of GDDR4/GDDR3/DDR3/DDR2 RAM. It features 320(64x5) SPUs as well as 32 Texture Address Units and 8 Rasterization Operator Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Theoretically, the Radeon HD 4670 1GB should perform a little bit faster than the Radeon HD 4670 512MB overall. (explain)
Texel RateBoth cards have the exact same texel rate, so theoretically they should perform equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have the exact same pixel rate, so theoretically they should perform equally good at at anti-aliasing, and be able to handle 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 megabytes per second) that can be transported past the external memory interface in one second. It is calculated by multiplying the interface width by its memory speed. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better 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 texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to the local memory per 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 sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.