Compare any two graphics cards:
Radeon HD 6670 (OEM) vs Radeon HD 7770
IntroThe Radeon HD 6670 (OEM) has a GPU clock speed of 800 MHz, and the 512 MB of GDDR5 memory runs at 1000 MHz through a 128-bit bus. It also is made up of 480 Stream Processors, 24 TAUs, and 8 Raster Operation Units.
Compare those specs to the Radeon HD 7770, which has a core clock speed of 1000 MHz and a GDDR5 memory speed of 1125 MHz. It also features a 128-bit memory bus, and uses a 28 nm design. It features 640 SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7770 is 13% quicker than the Radeon HD 6670 (OEM) overall, because of its greater data rate. (explain)
Texel RateThe Radeon HD 7770 will be a lot (about 108%) faster with regards to anisotropic filtering than the Radeon HD 6670 (OEM). (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7770 is the winner, by a large margin. (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 megabytes per second) that can be moved across the external memory interface within a second. The number is worked out by multiplying the bus width by the speed of its memory. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This is worked out by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.