Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB comes with a GPU core 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 TAUs, and 8 ROPs.
Compare that to the Radeon HD 7750, which features GPU clock speed of 800 MHz, and 1024 MB of GDDR5 memory running at 1125 MHz through a 128-bit bus. It also features 512 SPUs, 32 Texture Address Units, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
The Radeon HD 7750 should theoretically be a lot faster than the Radeon HD 4650 512MB in general. (explain)
Texel RateThe Radeon HD 7750 will be quite a bit (about 33%) faster with regards to AF than the Radeon HD 4650 512MB. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 7750 is the winner, and very much so. (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 MB per second) that can be transported across the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory speed. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, 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 texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called 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, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.