Compare any two graphics cards:
Radeon HD 6670 (OEM) vs Radeon HD 7770
IntroThe Radeon HD 6670 (OEM) has core speeds of 800 MHz on the GPU, and 1000 MHz on the 512 MB of GDDR5 memory. It features 480 SPUs as well as 24 TAUs and 8 Rasterization Operator Units.
Compare all that to the Radeon HD 7770, which comes with core clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 640 SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7770 should be 13% faster than the Radeon HD 6670 (OEM) in general, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 7770 should be quite a bit (approximately 108%) faster with regards to anisotropic filtering than the Radeon HD 6670 (OEM). (explain)
Pixel RateThe Radeon HD 7770 should be a lot (more or less 150%) faster with regards to AA than the Radeon HD 6670 (OEM), and also should be able to handle higher screen resolutions without slowing down too much. (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 largest amount of information (measured in megabytes per second) that can be transferred over the external memory interface in one second. It's worked out by multiplying the interface width by its memory speed. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This number is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.