Compare any two graphics cards:
Radeon HD 4850 1GB vs Radeon HD 7770
IntroThe Radeon HD 4850 1GB has a GPU core clock speed of 625 MHz, and the 1024 MB of GDDR4 memory is set to run at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.
Compare all that to the Radeon HD 7770, which makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 RAM is set to run at a frequency of 1125 MHz on this card. It features 640 SPUs as well as 40 Texture Address Units and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7770 should be 13% faster than the Radeon HD 4850 1GB in general, because of its greater data rate. (explain)
Texel RateThe Radeon HD 7770 is much (approximately 60%) faster with regards to anisotropic filtering than the Radeon HD 4850 1GB. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 7770 is the winner, by far. (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 max amount of information (counted in MB per second) that can be moved over the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied 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 higher this number, the better the card will be at handling 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 can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.