Compare any two graphics cards:
GeForce 8500 GT vs Radeon HD 5450
IntroThe GeForce 8500 GT features a GPU core speed of 450 MHz, and the 512 MB of DDR2 memory runs at 400 MHz through a 128-bit bus. It also features 16 SPUs, 8 TAUs, and 4 ROPs.
Compare those specifications to the Radeon HD 5450, which comes with a core clock speed of 650 MHz and a DDR3 memory speed of 800 MHz. It also uses a 64-bit memory bus, and makes use of a 40 nm design. It is made up of 80(16x5) SPUs, 8 Texture Address Units, and 4 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same bandwidth, so theoretically they should perform exactly the same. (explain)
Texel RateThe Radeon HD 5450 will be quite a bit (about 44%) better at anisotropic filtering than the GeForce 8500 GT. (explain)
Pixel RateThe Radeon HD 5450 should be a lot (approximately 44%) faster with regards to FSAA than the GeForce 8500 GT, and will be capable of handling higher screen resolutions without losing too much performance. (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 (counted in megabytes per second) that can be moved over the external memory interface in a second. It is worked out by multiplying the bus width by its memory speed. If it uses DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, 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 applied in one second. This number is worked out by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the video 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 amount of pixels the video card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.