Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7770
IntroThe Radeon HD 5870 features a clock speed of 850 MHz and a GDDR5 memory speed of 1200 MHz. It also features a 256-bit bus, and uses a 40 nm design. It features 1600(320x5) SPUs, 80 TAUs, and 32 ROPs.
Compare all that to the Radeon HD 7770, which has a GPU core 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 made up of 640 SPUs, 40 TAUs, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5870 is 113% faster than the Radeon HD 7770 overall, due to its higher data rate. (explain)
Texel RateThe Radeon HD 5870 will be a lot (about 70%) faster with regards to AF than the Radeon HD 7770. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 5870 is superior to the Radeon HD 7770, and very much so. (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 maximum amount of information (in units of MB per second) that can be transported past the external memory interface in a second. The number is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the 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 can be applied per second. This is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The better this number, the better the graphics 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 graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.