Currently the best integrated Intel graphics core is the Intel HD 3000. This graphics core is in all laptop Sandy Bridge Core i3/i5/i7 CPUs, but only in the Core i5-2500K and Core i7-2600k desktop CPUs.
The Intel HD 3000 is slightly better than the Radeon HD 5450, but is slower than the nVidia GT 220. See following benchmarks to get a rough idea of performance.
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Internal igps are for general 2D viewing (Internet/word processor/email) and watching a dvd/Blu-ray movie. They are very poor for gaming with setting above the Min.