Compare any two graphics cards:
GeForce GT 640 DDR3 vs GeForce GTX 650 Ti 2GB
IntroThe GeForce GT 640 DDR3 features a clock speed of 900 MHz and a DDR3 memory frequency of 1782 MHz. It also uses a 128-bit bus, and makes use of a 28 nm design. It features 384 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare those specs to the GeForce GTX 650 Ti 2GB, which features a clock speed of 928 MHz and a GDDR5 memory frequency of 1350 MHz. It also uses a 128-bit memory bus, and makes use of a 28 nm design. It is comprised of 768 SPUs, 64 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 650 Ti 2GB is 52% faster than the GeForce GT 640 DDR3 in general, due to its greater data rate. (explain)
Texel RateThe GeForce GTX 650 Ti 2GB should be a lot (about 106%) faster with regards to AF than the GeForce GT 640 DDR3. (explain)
Pixel RateThe GeForce GTX 650 Ti 2GB is a bit (approximately 3%) more effective at AA than the GeForce GT 640 DDR3, and should be able to handle 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: Memory bandwidth is the maximum amount of information (in units of megabytes per second) that can be transported past the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory speed. If the card has DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, 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 texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.