Compare any two graphics cards:
GeForce 8600 GT 512MB DDR2 vs Radeon HD 5450
IntroThe GeForce 8600 GT 512MB DDR2 has a GPU core speed of 540 MHz, and the 512 MB of DDR2 RAM is set to run at 400 MHz through a 128-bit bus. It also is made up of 32 Stream Processors, 16 Texture Address Units, and 8 Raster Operation Units.
Compare all that to the Radeon HD 5450, which uses a 40 nm design. AMD has set the core frequency at 650 MHz. The DDR3 RAM runs at a frequency of 800 MHz on this model. It features 80(16x5) SPUs along with 8 Texture Address Units and 4 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same memory bandwidth, so theoretically they should have identical performance. (explain)
Texel RateThe GeForce 8600 GT 512MB DDR2 will be quite a bit (more or less 66%) better at texture filtering than the Radeon HD 5450. (explain)
Pixel RateThe GeForce 8600 GT 512MB DDR2 should be a lot (about 66%) faster with regards to AA than the Radeon HD 5450, and capable of handling higher resolutions more effectively. (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 maximum amount of data (measured in megabytes per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the interface width by the speed of its memory. If the card has DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This number is worked out by multiplying the total texture units by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could 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 colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.