Compare any two graphics cards:
GeForce 8500 GT vs Radeon HD 5450
IntroThe GeForce 8500 GT uses a 80 nm design. nVidia has set the core frequency at 450 MHz. The DDR2 RAM is set to run at a speed of 400 MHz on this particular card. It features 16 SPUs as well as 8 Texture Address Units and 4 ROPs.
Compare that to the Radeon HD 5450, which features core clock speeds of 650 MHz on the GPU, and 800 MHz on the 512 MB of DDR3 memory. It features 80(16x5) SPUs as well as 8 Texture Address Units and 4 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same bandwidth, so in theory they should have identical performance. (explain)
Texel RateThe Radeon HD 5450 should be quite a bit (about 44%) faster with regards to anisotropic filtering than the GeForce 8500 GT. (explain)
Pixel RateThe Radeon HD 5450 will be a lot (more or less 44%) faster with regards to AA than the GeForce 8500 GT, and 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: Memory bandwidth is the max amount of information (in units of MB per second) that can be transported across the external memory interface in one second. The number is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the 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 texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.