Compare any two graphics cards:
Radeon HD 4850 1GB vs Radeon HD 7770
IntroThe Radeon HD 4850 1GB makes use of a 55 nm design. AMD has set the core speed at 625 MHz. The GDDR4 RAM works at a frequency of 993 MHz on this specific card. It features 800(160x5) SPUs as well as 40 TAUs and 16 Rasterization Operator Units.
Compare all that to the Radeon HD 7770, which comes with clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7770 should perform a bit faster than the Radeon HD 4850 1GB overall. (explain)
Texel RateThe Radeon HD 7770 is much (approximately 60%) more effective at AF than the Radeon HD 4850 1GB. (explain)
Pixel RateThe Radeon HD 7770 is much (about 60%) better at full screen anti-aliasing than the Radeon HD 4850 1GB, and also able to handle higher 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 maximum amount of information (counted in MB per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the bus width by its memory speed. If it uses DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of 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 rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.