Benchmarking zones

In customer presentations about Zones there is an always reoccuring questing. How huge is the performance impact of virtualisation. Most of them have some experience with VMware and it´s rather high impact (unfortunately the VMware licence conditions don´t allow independent benchmarks, so there are no real public numbers about this) or with other virtualization technolgies. Most of the time, they don´t believe that the impact is almost ignorable. We ran some benchmarks with SAP-SD, that clearly show that zones have only an impact of less than 1% (even less than the 3-4 % i use as a safe harbour statement in presentations).
Apropos Zones: There are two interesting pages around this topic: At opensolaris.org you can look at the state of certain extensions to the Zones implementation. And at sun.com you find a guide about the integration of ZFS and Zones.