Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 7750
IntroThe GeForce GT 640 DDR3 features core speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 RAM. It features 384 SPUs as well as 32 Texture Address Units and 16 Rasterization Operator Units.
Compare those specifications to the Radeon HD 7750, which has GPU core speed of 800 MHz, and 1024 MB of GDDR5 memory set to run at 1125 MHz through a 128-bit bus. It also is comprised of 512 Stream Processors, 32 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7750 should in theory perform much faster than the GeForce GT 640 DDR3 overall. (explain)
Texel RateThe GeForce GT 640 DDR3 will be a little bit (approximately 13%) more effective at AF than the Radeon HD 7750. (explain)
Pixel RateIf running with a high resolution is important to you, then the GeForce GT 640 DDR3 is the winner, though only just barely. (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 (counted in megabytes per second) that can be transported past the external memory interface within a second. It is calculated by multiplying the bus width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number 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 by the core clock speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.