Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB comes with a core clock speed of 600 MHz and a DDR2 memory speed of 500 MHz. It also makes use of a 128-bit bus, and uses a 55 nm design. It features 320(64x5) SPUs, 32 Texture Address Units, and 8 Raster Operation Units.
Compare all that to the Radeon HD 7750, which features GPU core speed of 800 MHz, and 1024 MB of GDDR5 memory running at 1125 MHz through a 128-bit bus. It also features 512 Stream Processors, 32 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Theoretically speaking, the Radeon HD 7750 should be 350% quicker than the Radeon HD 4650 512MB in general, because of its greater data rate. (explain)
Texel RateThe Radeon HD 7750 is much (approximately 33%) faster with regards to texture filtering than the Radeon HD 4650 512MB. (explain)
Pixel RateThe Radeon HD 7750 will be much (approximately 167%) more effective at FSAA than the Radeon HD 4650 512MB, and also should be able to handle higher screen resolutions without losing too much performance. (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 (in units of megabytes per second) that can be transferred across the external memory interface within a second. It is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This number is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.