Hello everyone.

I am avid virtualization user, and that's why bought Crosshair IV Extreme - wanted IOMMU, among other things of course.

But each time I enable this option in BIOS, system won't boot - get stuck on VGA POST test (at least that't what the light on motherboard says). My PSU is 1200, motherboard was replaced, and the same problem happens on both. Everything else works fine as long as I do not enable IOMMU. (well, apart from infamous north bridge temperature problem).

Has anyone here had similar problem? Am I missing something obvious?

I also have 16Gb of RAM and 7 hard drives :) but still I think that 1200 should handle it without a hassle. Also system used to work (again, without IOMMU) fine on 650 PSU. In fact, I just replaced that 650 to 1200 today because I thought that maybe IOMMU needs more power.

Anyway, any help will be appreciated.