Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB has a GPU core clock speed of 600 MHz, and the 512 MB of DDR2 memory runs at 500 MHz through a 128-bit bus. It also features 320(64x5) SPUs, 32 Texture Address Units, and 8 ROPs.
Compare all that to the Radeon HD 7750, which comes with GPU clock speed of 800 MHz, and 1024 MB of GDDR5 memory set to run at 1125 MHz through a 128-bit bus. It also features 512 Stream Processors, 32 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Theoretically speaking, the Radeon HD 7750 will be 350% quicker than the Radeon HD 4650 512MB in general, because of its higher data rate. (explain)
Texel RateThe Radeon HD 7750 should be much (approximately 33%) faster with regards to anisotropic filtering than the Radeon HD 4650 512MB. (explain)
Pixel RateThe Radeon HD 7750 should be much (about 167%) more effective at AA than the Radeon HD 4650 512MB, and also able to handle higher screen resolutions better. (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 (measured in megabytes per second) that can be transported over the external memory interface in a second. It is worked out by multiplying the interface width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, 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 can be processed per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher 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 number of pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out 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 outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.