Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 7770
IntroThe Radeon HD 6770 features a clock frequency of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also uses a 128-bit memory bus, and uses a 40 nm design. It features 800 SPUs, 40 Texture Address Units, and 16 ROPs.
Compare those specifications to the Radeon HD 7770, which makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 memory works at a speed of 1125 MHz on this specific card. It features 640 SPUs along with 40 TAUs and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7770 should theoretically be a little bit superior to the Radeon HD 6770 overall. (explain)
Texel RateThe Radeon HD 7770 should be a small bit (approximately 11%) faster with regards to texture filtering than the Radeon HD 6770. (explain)
Pixel RateThe Radeon HD 7770 is a little bit (approximately 11%) better at FSAA than the Radeon HD 6770, and should be capable of handling 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: Memory bandwidth is the largest amount of information (in units of megabytes per second) that can be moved across the external memory interface in a second. It's worked out by multiplying the interface width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 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, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total number of texture units by the core 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 processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka 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 memory bandwidth is, the lower the ability to reach the max fill rate.