Compare any two graphics cards:
Radeon HD 4650 1GB vs Radeon HD 7750
IntroThe Radeon HD 4650 1GB has a core clock speed of 600 MHz and a GDDR3 memory speed of 700 MHz. It also features a 128-bit bus, and makes use of a 55 nm design. It features 320(64x5) SPUs, 32 TAUs, and 8 Raster Operation Units.
Compare all that to the Radeon HD 7750, which has core speeds of 800 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 memory. It features 512 SPUs along with 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.
Theoretically speaking, the Radeon HD 7750 should be 221% quicker than the Radeon HD 4650 1GB overall, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 7750 will be much (more or less 33%) better at AF than the Radeon HD 4650 1GB. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 7750 is the winner, by far. (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 max amount of data (counted in megabytes per second) that can be transferred past the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.