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Re: [Xen-users] ASRock B85M Pro4 micro-ATX Motherboard Supports VT-d!!!

Nice to hear confirmation about this. I have been spending many months gathering data regarding both Hardware and Firmware/BIOS support for both Intel VT-d and AMD-Vi, and I was waiting to get confirmation on Haswell Chipsets/Motherboards before getting one.

There was a Thread one month ago of a guy that speaked to AsRock support, and they said that they provide support for VT-d in all current Haswell Desktop Chipsets-based Motherboards, specifically B85, H87, Z87, and Q87:


You confirmed that B85 works. AsRock seems to be currently the vendor that is providing the best support for VT-d in Desktop Motherboards.

Supermicro also mentions prominently in the Manual of the Z87-based C7Z87 and C7Z87-OCE Motherboards that it got VT-d support:


While not tested, I believe it should work due to Supermicro reputation in the Server market. Besides, while on Manuals from other Motherboards brands they just say that they have an option to enable or disable VT-d (Something like "Turn on this option to enable Intel virtualization technology"), the Manual from those two Motherboards actually do makes mention of what VT-d is for, and talks about the ACPI DMAR table, adding to their credibility that they know what they're talking about.

ASUS on the other hand, told me that they don't support VT-d on anything else but Q-series Chipsets because it fails some tests they do, but without information about what tests those are, I can't take them serious considering that there are a lot of people that successfully used VT-d on all the other Chipsets:


He also mentioned somewhere on other forum that there is a official Intel utility to verify VT-d support, but doesn't seem to be available to the public, because is nowhere to be found:


Besides that, ASUS got mediocre support for AMD-Vi last time I checked. 890FX and 990FX Chipsets had the required IOMMU, but the BIOS ACPI IVRS tables of most BIOS from ASUS Motherboards were usually broken. They can't blame the Chipset on those ones, is simply that their BIOS developers don't even care about spending time to implement this feature.

Finally, Intel has a webpage where they say that in order to have VT-d support, you only need Processor and BIOS support for it. It doesn't mention requiring a specific Chipset. It also says that Intel got a B85 Motherboard that supports VT-d:


However, the issue comes from Intel Ark data. If you check the Chipsets:


It says that only Q87, C222 and C226 have VT-d support, with a no for all the others, including B85. Not only that based on experience this data seems to be wrong, but is also wrong on previous generations Chipsets specs, because VT-d was reported as working in many Sandy Bridge and Ivy Bridge Chipsets that Intel Ark said they does not work with it (Yet Intel also claimed VT-d support on some Intel branded Motherboards using those Chipsets, from the previous link). It also doesn't make sense, because the IOMMU was moved from the Chipset to the Processor itself at Nehalem era.
This info from Intel Ark is what has been misleading people all along. I would love to get a official word from Intel about what should work, and what should not, and that after no less than three years, they fix those specs and contradicting info.

At least, after spending several months trying to get real facts about what you need to get working support for this feature, now I could say that I can purchase either AsRock or Supermicro with confidence that they will work with VT-d.
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