Compare any two graphics cards:
GeForce GTS 450 1GB vs Radeon HD 4850 1GB
IntroThe GeForce GTS 450 1GB comes with clock speeds of 783 MHz on the GPU, and 902 MHz on the 1024 MB of GDDR5 RAM. It features 192 SPUs along with 32 Texture Address Units and 16 ROPs.
Compare those specifications to the Radeon HD 4850 1GB, which uses a 55 nm design. AMD has set the core frequency at 625 MHz. The GDDR4 RAM runs at a frequency of 993 MHz on this particular model. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 4850 1GB should perform a bit faster than the GeForce GTS 450 1GB overall. (explain)
Texel RateThe GeForce GTS 450 1GB should be a little bit (about 0%) more effective at AF than the Radeon HD 4850 1GB. (explain)
Pixel RateIf using a high screen resolution is important to you, then the GeForce GTS 450 1GB 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 megabytes per second) that can be transferred across the external memory interface in one second. It is worked out by multiplying the interface width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster 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 can be applied in one second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.