Compare any two graphics cards:
GeForce GT 340 1GB vs Radeon HD 4870 512MB
IntroThe GeForce GT 340 1GB has a GPU core speed of 550 MHz, and the 1024 MB of GDDR5 RAM runs at 850 MHz through a 128-bit bus. It also is made up of 96 SPUs, 32 TAUs, and 8 ROPs.
Compare those specifications to the Radeon HD 4870 512MB, which features a clock speed of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also features a 256-bit memory bus, and uses a 55 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 4870 512MB, in theory, should perform quite a bit faster than the GeForce GT 340 1GB overall. (explain)
Texel RateThe Radeon HD 4870 512MB will be much (about 70%) more effective at anisotropic filtering than the GeForce GT 340 1GB. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the Radeon HD 4870 512MB is a better choice, 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: Bandwidth is the largest amount of information (in units of MB per second) that can be transferred across the external memory interface within a second. It's calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is calculated by multiplying the total amount of texture units of the card by the core 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 applied in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.