Compare any two graphics cards:
Radeon HD 5670 vs Radeon HD 5770
IntroThe Radeon HD 5670 has a GPU core speed of 775 MHz, and the 1024 MB of GDDR5 memory runs at 1000 MHz through a 128-bit bus. It also is made up of 400(80x5) Stream Processors, 20 TAUs, and 8 ROPs.
Compare that to the Radeon HD 5770, which has a core clock speed of 850 MHz and a GDDR5 memory frequency of 1200 MHz. It also makes use of a 128-bit memory bus, and uses a 40 nm design. It is made up of 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5770 should perform a small bit faster than the Radeon HD 5670 overall. (explain)
Texel RateThe Radeon HD 5770 is a lot (about 119%) more effective at texture filtering than the Radeon HD 5670. (explain)
Pixel RateThe Radeon HD 5770 is a lot (approximately 119%) more effective at FSAA than the Radeon HD 5670, and also capable of handling higher 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: Memory bandwidth is the largest amount of data (in units of MB per second) that can be transported past the external memory interface in a second. It's calculated by multiplying the interface width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 again. If it uses 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 processed in one second. This is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.