Compare any two graphics cards:
GeForce GTX 880M vs Radeon HD 5870
IntroThe GeForce GTX 880M features clock speeds of 954 MHz on the GPU, and 1000 MHz on the 4096 MB of GDDR5 memory. It features 1536 SPUs along with 128 Texture Address Units and 32 Rasterization Operator Units.
Compare all that to the Radeon HD 5870, which has a GPU core clock speed of 850 MHz, and 1024 MB of GDDR5 memory set to run at 1200 MHz through a 256-bit bus. It also is comprised of 1600(320x5) SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5870 should be 20% faster than the GeForce GTX 880M overall, due to its greater data rate. (explain)
Texel RateThe GeForce GTX 880M will be quite a bit (about 80%) more effective at texture filtering than the Radeon HD 5870. (explain)
Pixel RateIf using high levels of AA is important to you, then the GeForce GTX 880M is the winner, but not by far. (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 (measured in megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the bus width by the speed of its memory. If the card has DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better 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 amount of texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.