Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 6670 (OEM) 1GB
IntroThe GeForce GT 640 DDR3 comes with a core clock frequency of 900 MHz and a DDR3 memory speed of 1782 MHz. It also makes use of a 128-bit memory bus, and uses a 28 nm design. It features 384 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare all of that to the Radeon HD 6670 (OEM) 1GB, which has a GPU core clock speed of 800 MHz, and 1024 MB of GDDR5 memory set to run at 1000 MHz through a 128-bit bus. It also is comprised of 480 Stream Processors, 24 Texture Address Units, and 8 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6670 (OEM) 1GB is 12% quicker than the GeForce GT 640 DDR3 overall, because of its greater data rate. (explain)
Texel RateThe GeForce GT 640 DDR3 will be a lot (approximately 50%) faster with regards to AF than the Radeon HD 6670 (OEM) 1GB. (explain)
Pixel RateThe GeForce GT 640 DDR3 is a lot (about 125%) more effective at full screen anti-aliasing than the Radeon HD 6670 (OEM) 1GB, and also will be able to handle higher screen resolutions while still performing well. (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 max amount of information (in units of megabytes per second) that can be moved across the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total number of texture units of the card by the core clock 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 applied per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.