Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 6450 (OEM) 1GB
IntroThe Radeon HD 4650 512MB features a clock speed of 600 MHz and a DDR2 memory frequency of 500 MHz. It also makes use of a 128-bit bus, and makes use of a 55 nm design. It features 320(64x5) SPUs, 32 Texture Address Units, and 8 ROPs.
Compare all that to the Radeon HD 6450 (OEM) 1GB, which comes with a clock frequency of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also uses a 64-bit bus, and uses a 40 nm design. It is made up of 160 SPUs, 8 TAUs, and 4 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 6450 (OEM) 1GB should theoretically be quite a bit better than the Radeon HD 4650 512MB in general. (explain)
Texel RateThe Radeon HD 4650 512MB will be a lot (more or less 220%) faster with regards to AF than the Radeon HD 6450 (OEM) 1GB. (explain)
Pixel RateThe Radeon HD 4650 512MB will be much (more or less 60%) more effective at AA than the Radeon HD 6450 (OEM) 1GB, and also able to handle higher screen resolutions without slowing down too much. (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 (in units of megabytes per second) that can be transferred across the external memory interface in one second. The number is calculated by multiplying the bus width by its memory speed. If the card has DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 are processed per second. This figure is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to the 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 speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.