Compare any two graphics cards:
Radeon HD 4670 1GB vs Radeon HD 4670 512MB
IntroThe Radeon HD 4670 1GB features a clock speed of 750 MHz and a GDDR4/GDDR3/DDR3/DDR2 memory frequency of 1100 MHz. It also features a 128-bit memory bus, and uses a 55 nm design. It is comprised of 320(64x5) SPUs, 32 TAUs, and 8 ROPs.
Compare those specifications to the Radeon HD 4670 512MB, which has GPU clock speed of 750 MHz, and 512 MB of GDDR4/GDDR3/DDR3/DDR2 memory set to run at 1000 MHz through a 128-bit bus. It also features 320(64x5) Stream Processors, 32 TAUs, and 8 Raster Operation Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Theoretically speaking, the Radeon HD 4670 1GB should be 10% faster than the Radeon HD 4670 512MB in general, because of its higher data rate. (explain)
Texel RateBoth cards have exactly the same texel rate, so in theory they should perform equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have the exact same pixel rate, so theoretically they should be equally good at at AA, 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 information (counted in MB per second) that can be transferred over the external memory interface within a second. The number is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, 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 amount of texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total texture units 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 in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.