[CentOS] is Intel VT-d "really" necessary?

Emmanuel Noobadmin centos.admin at gmail.com
Wed Sep 15 22:36:33 EDT 2010


Hi,

> I'm just curios and would like some input from the community on this
> one. We're busy budgeting for a couple of new servers and I thought it
> would be good to try out the Core i7 CPU's, but see the majority of
> them don't offer VT-d, but just VT-x. Looking at the LGA1366 range,
> only the "Intel lga1366 i7 980XE" (from the list of what our suppliers
> stock) have VT-d, and it costs 4x more than "Intel lga1366 i7 930" or
> 2x more than "Intel lga1366 i7 960".

How about the Xeon processors? Are they cheaper than the i7-980XE
there? Also keep in mind your board has to support VT-D as well.

>From a budget perspecitve I could
> purchase 4 more CPU's, which could translate to 40x - 80x more VM's
> being hosted for the same capital outlay. Experience has shown that we
> under-utilize CPU's by a great margin and memory / HDD IO is our
> biggest bottleneck on any server.

>From this it seems that you would be running 10 to 20 VM per machine.
According to Intel, it's not recommended if the physical NIC is
shared. So in your case, the VT-d issue might be moot.


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