Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 6450 (OEM) 1GB
IntroThe Radeon HD 4650 512MB has a clock frequency of 600 MHz and a DDR2 memory speed of 500 MHz. It also makes use of a 128-bit bus, and uses a 55 nm design. It features 320(64x5) SPUs, 32 TAUs, and 8 ROPs.
Compare those specs to the Radeon HD 6450 (OEM) 1GB, which features a GPU core clock speed of 750 MHz, and 1024 MB of GDDR5 RAM set to run at 900 MHz through a 64-bit bus. It also is made up of 160 Stream Processors, 8 Texture Address Units, and 4 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6450 (OEM) 1GB should perform much faster than the Radeon HD 4650 512MB in general. (explain)
Texel RateThe Radeon HD 4650 512MB is much (about 220%) better at AF than the Radeon HD 6450 (OEM) 1GB. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 4650 512MB is a better choice, by a large margin. (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 information (measured in MB per second) that can be moved across the external memory interface in one second. It is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR type 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 AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the the core 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 fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.