Compare any two graphics cards:
GeForce 8800 GTS (G80) 640MB vs Radeon HD 4650 1GB
IntroThe GeForce 8800 GTS (G80) 640MB comes with a GPU clock speed of 513 MHz, and the 640 MB of GDDR3 memory is set to run at 792 MHz through a 320-bit bus. It also is made up of 96 Stream Processors, 48 Texture Address Units, and 20 Raster Operation Units.
Compare that to the Radeon HD 4650 1GB, which features core speeds of 600 MHz on the GPU, and 700 MHz on the 1024 MB of GDDR3 RAM. It features 320(64x5) SPUs as well as 32 Texture Address Units and 8 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the GeForce 8800 GTS (G80) 640MB should in theory be quite a bit superior to the Radeon HD 4650 1GB in general. (explain)
Texel RateThe GeForce 8800 GTS (G80) 640MB is quite a bit (about 28%) better at anisotropic filtering than the Radeon HD 4650 1GB. (explain)
Pixel RateThe GeForce 8800 GTS (G80) 640MB is a lot (about 114%) better at FSAA than the Radeon HD 4650 1GB, and should be capable of handling higher 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 maximum amount of data (in units of megabytes per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This number is worked out 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 graphics 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 amount of pixels that the graphics chip can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.