The new Ivy Bridge processors introduced a new member of Intel's graphics processor called the HD 2500, which has received less than positive reviews as the previous HD 3000 outperforms it.  However those tests were for Windows applications and games, whereas the testing at Phoronix specifically pertains to the performance under Linux.  They compare the i5-2400S, i5-2500K, i5-3470, and i7-3770K together in a series of benchmarks to not only test the performance but also their compatibility with Linux.  It seems that perhaps the performance of the HD3000 and HD2500 are much closer in Linux than they were running under Windows, though both still lose out to the HD4000.

"Since the launch of Intel's Ivy Bridge processors earlier this year there have been many benchmarks of the Intel Core i7 3770K with its integrated HD 4000 graphics and then more recently have been Linux testing of the Intel Core i7 3517UE from the CompuLab Intense-PC and Intel Core i7-3615QM as found on the Apple Retina MacBook Pro. The newest Intel Ivy Bridge chip to play with at Phoronix is the Intel Core i5 3470, which bears an Intel HD 2500 graphics core. In this article are benchmarks of the Intel HD 2500 Ivy Bridge graphics with the open-source Intel Linux graphics driver stack."

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Processors