Compare any two graphics cards:
Radeon HD 4650 1GB vs Radeon HD 7750
IntroThe Radeon HD 4650 1GB has a core clock frequency of 600 MHz and a GDDR3 memory speed of 700 MHz. It also uses a 128-bit bus, and uses a 55 nm design. It is comprised of 320(64x5) SPUs, 32 TAUs, and 8 ROPs.
Compare that to the Radeon HD 7750, which features a clock speed of 800 MHz and a GDDR5 memory speed of 1125 MHz. It also uses a 128-bit bus, and uses a 28 nm design. It is comprised of 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.
Theoretically speaking, the Radeon HD 7750 should be 221% faster than the Radeon HD 4650 1GB in general, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 7750 is quite a bit (more or less 33%) more effective at AF than the Radeon HD 4650 1GB. (explain)
Pixel RateThe Radeon HD 7750 should be much (about 167%) faster with regards to AA than the Radeon HD 4650 1GB, and should be capable of handling higher screen resolutions more effectively. (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 maximum amount of data (measured in megabytes per second) that can be transported past the external memory interface in a second. The number is worked out by multiplying the card's interface width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, 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 number of texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the video card will be at handling 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 write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.