Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB has a core clock frequency of 600 MHz and a DDR2 memory frequency of 500 MHz. It also makes use of a 128-bit memory bus, and uses a 55 nm design. It is made up of 320(64x5) SPUs, 32 TAUs, and 8 Raster Operation Units.
Compare all that to the Radeon HD 7750, which features a core clock frequency of 800 MHz and a GDDR5 memory speed of 1125 MHz. It also makes use of a 128-bit memory bus, and uses a 28 nm design. It is comprised of 512 SPUs, 32 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
In theory, the Radeon HD 7750 should perform quite a bit faster than the Radeon HD 4650 512MB in general. (explain)
Texel RateThe Radeon HD 7750 should be much (about 33%) faster with regards to texture filtering than the Radeon HD 4650 512MB. (explain)
Pixel RateThe Radeon HD 7750 will be a lot (more or less 167%) better at full screen anti-aliasing than the Radeon HD 4650 512MB, and also should be capable of handling 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: Memory bandwidth is the maximum amount of data (in units of megabytes per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, the better the graphics 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 amount of pixels the graphics card 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 number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few 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.