By mrj on Mar 30, 2009
There are features which are easy to see, such as the integrated memory controllers and the Quick Path Interconnects (QPI) (which connect the CPUs and IO bridges to each other).
But, as you would expect, they also continue to improve the guts of the CPUs. For example, with the 5500 series and associated IO chipsets, comes virtualization improvements including better virtualized CPU performance, and the ability to safely passthrough an IO device to a virtualized guest.
With Intel's help, we backported a lot of the new functionality from xen-unstable.hg into OpenSolaris xVM in April of 2008, including the big ones, Extended Page Table (EPT) support and Virtual Processor IDs (VPID). So we've been ready for a while :-)
With the EPT support, you can bypass the shadow page code in the hypervisor for fully virtualized guests. This gives you a nice performance improvement, and has the added benefit of a not having to run a \*lot\* of complex, and occasionally, buggy code.
I've just scratched the surface of the virtualization improvements in the Intel Xeon 5500 series. For folks who enjoy CPU technology, we live in exciting times.