Compare any two graphics cards:
Radeon HD 4650 1GB vs Radeon HD 7750
IntroThe Radeon HD 4650 1GB comes with a core clock frequency of 600 MHz and a GDDR3 memory frequency of 700 MHz. It also uses a 128-bit memory bus, and makes use of a 55 nm design. It is made up of 320(64x5) SPUs, 32 Texture Address Units, 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 uses a 128-bit bus, and makes use of a 28 nm design. It is made up 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 quite a bit faster than the Radeon HD 4650 1GB overall. (explain)
Texel RateThe Radeon HD 7750 will be a lot (more or less 33%) more effective at anisotropic filtering than the Radeon HD 4650 1GB. (explain)
Pixel RateThe Radeon HD 7750 is quite a bit (about 167%) faster with regards to AA than the Radeon HD 4650 1GB, and should be capable of handling higher screen resolutions without losing too much performance. (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 max amount of data (measured in megabytes per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the bus width by the speed of its memory. If it uses DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.