Compare any two graphics cards:
GeForce GTX 295 vs Geforce GTX 680
IntroThe GeForce GTX 295 has a GPU core clock speed of 576 MHz, and the 896 MB of GDDR3 RAM is set to run at 999 MHz through a 448-bit bus. It also is made up of 240 Stream Processors, 80 TAUs, and 28 Raster Operation Units.
Compare those specs to the Geforce GTX 680, which has a core clock speed of 1006 MHz and a GDDR5 memory frequency of 1502 MHz. It also makes use of a 256-bit bus, and uses a 28 nm design. It features 1536 SPUs, 128 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce GTX 295 should be 16% faster than the Geforce GTX 680 overall, due to its greater bandwidth. (explain)
Texel RateThe Geforce GTX 680 is a lot (about 40%) better at anisotropic filtering than the GeForce GTX 295. (explain)
Pixel RateIf using a high screen resolution is important to you, then the GeForce GTX 295 is superior to the Geforce GTX 680, 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.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
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 information (measured in MB per second) that can be transferred across the external memory interface within a second. It is worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR RAM, it must be multiplied by 2 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 are processed per second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, 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 number of pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.