Compare any two graphics cards:
Radeon HD 4730 vs Radeon HD 4850 512MB
IntroThe Radeon HD 4730 comes with a GPU clock speed of 700 MHz, and the 512 MB of GDDR5 memory is set to run at 900 MHz through a 128-bit bus. It also features 640(128x5) SPUs, 32 TAUs, and 8 Raster Operation Units.
Compare those specs to the Radeon HD 4850 512MB, which features a core clock speed of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also uses a 256-bit memory bus, and uses a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 4850 512MB should in theory be a small bit faster than the Radeon HD 4730 overall. (explain)
Texel RateThe Radeon HD 4850 512MB is just a bit (approximately 12%) better at anisotropic filtering than the Radeon HD 4730. (explain)
Pixel RateThe Radeon HD 4850 512MB is a lot (approximately 79%) more effective at AA than the Radeon HD 4730, and also should be able to handle higher resolutions while still performing well. (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 transported past 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 RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, 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 can be applied in one second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the video 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 most pixels the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.