[wtallis]

Mainstream consumer x86 processors have had IOMMU capability for over a decade, but for the first few years it was commonly disabled on certain parts for product segmentation (eg. i5-3570K had overclocking but no IOMMU, i5-3570 had IOMMU but limited overclocking). That practice died off approximately when Thunderbolt started to catch on, because not having an IOMMU when using Thunderbolt would have been very bad.