Compare any two graphics cards:
Radeon HD 5750 1GB vs Radeon HD 7870 XT
IntroThe Radeon HD 5750 1GB makes use of a 40 nm design. AMD has clocked the core speed at 700 MHz. The GDDR5 RAM works at a frequency of 1150 MHz on this card. It features 720(144x5) SPUs along with 36 TAUs and 16 Rasterization Operator Units.
Compare those specifications to the Radeon HD 7870 XT, which has clock speeds of 925 MHz on the GPU, and 1500 MHz on the 2048 MB of GDDR5 RAM. It features 1536 SPUs as well as 96 Texture Address Units and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7870 XT should theoretically be quite a bit superior to the Radeon HD 5750 1GB in general. (explain)
Texel RateThe Radeon HD 7870 XT should be a lot (more or less 252%) faster with regards to AF than the Radeon HD 5750 1GB. (explain)
Pixel RateThe Radeon HD 7870 XT will be much (more or less 164%) faster with regards to full screen anti-aliasing than the Radeon HD 5750 1GB, and also will be capable of handling higher resolutions while still performing well. (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.
Memory Bandwidth: Bandwidth is the maximum amount of information (counted in megabytes per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the interface width by its memory speed. If the card has DDR RAM, the result should 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, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock 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 processed in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). 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 ability to get to the maximum fill rate.