Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 7750
IntroThe GeForce GT 640 DDR3 makes use of a 28 nm design. nVidia has set the core speed at 900 MHz. The DDR3 RAM works at a frequency of 1782 MHz on this card. It features 384 SPUs as well as 32 TAUs and 16 ROPs.
Compare those specifications to the Radeon HD 7750, which features GPU core speed of 800 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is comprised of 512 SPUs, 32 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7750 should in theory perform quite a bit faster than the GeForce GT 640 DDR3 overall. (explain)
Texel RateThe GeForce GT 640 DDR3 is a little bit (approximately 13%) faster with regards to AF than the Radeon HD 7750. (explain)
Pixel RateIf using a high screen resolution is important to you, then the GeForce GT 640 DDR3 is superior to the Radeon HD 7750, but it probably won't make a huge difference. (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 data (in units of MB per second) that can be transferred over the external memory interface within a second. The number is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better 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 amount of texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total number of texture units by the core clock 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 in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.