Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 7770
IntroThe Radeon HD 6790 makes use of a 40 nm design. AMD has set the core frequency at 840 MHz. The GDDR5 RAM runs at a speed of 1050 MHz on this particular model. It features 800 SPUs along with 40 Texture Address Units and 16 ROPs.
Compare those specifications to the Radeon HD 7770, which comes with GPU clock speed of 1000 MHz, and 1024 MB of GDDR5 RAM set to run at 1125 MHz through a 128-bit bus. It also is comprised of 640 SPUs, 40 TAUs, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6790 should theoretically perform much faster than the Radeon HD 7770 overall. (explain)
Texel RateThe Radeon HD 7770 is a small bit (approximately 19%) faster with regards to texture filtering than the Radeon HD 6790. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7770 is a better choice, 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 maximum amount of data (counted in MB per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the bus width by its memory clock speed. If the card has DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's 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 is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel 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 potential to reach the max fill rate.