Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 7770
IntroThe Radeon HD 6770 comes with a GPU clock speed of 900 MHz, and the 512 MB of GDDR5 memory is set to run at 1050 MHz through a 128-bit bus. It also is made up of 800 SPUs, 40 Texture Address Units, and 16 ROPs.
Compare those specs to the Radeon HD 7770, which makes use of a 28 nm design. AMD has set the core frequency at 1000 MHz. The GDDR5 RAM runs at a speed 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)
The Radeon HD 7770 should theoretically be a little bit faster than the Radeon HD 6770 overall. (explain)
Texel RateThe Radeon HD 7770 is just a bit (about 11%) faster with regards to texture filtering than the Radeon HD 6770. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7770 is superior to the Radeon HD 6770, though only just barely. (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 data (counted in MB per second) that can be transferred past 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 memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's 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 number of texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate 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 rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.