Compare any two graphics cards:
Radeon HD 5770 vs Radeon HD 7770
IntroThe Radeon HD 5770 comes with a GPU clock speed of 850 MHz, and the 1024 MB of GDDR5 RAM is set to run at 1200 MHz through a 128-bit bus. It also is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
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 particular model. It features 640 SPUs as well as 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5770 should be 7% faster than the Radeon HD 7770 in general, because of its greater data rate. (explain)
Texel RateThe Radeon HD 7770 will be a little bit (about 18%) faster with regards to AF than the Radeon HD 5770. (explain)
Pixel RateThe Radeon HD 7770 is just a bit (approximately 18%) faster with regards to FSAA than the Radeon HD 5770, and also should be able to handle higher screen resolutions better. (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 (measured in MB per second) that can be transported across the external memory interface in one second. The number is worked out by multiplying the interface width by the speed of its memory. In the case of DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, 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 most pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units 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 fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.