An anonymous reader writes "Compared to an operating-system-level virtualization technology like OpenVZ, Xen — a hypervisor-level virtualization technology that allows multiple operating systems to be run with and without para-virtualization — trades off performance for much better isolation and security. OpenVZ's performance advantage due to running virtual containers in a single operating system kernel can be significant. A performance evaluation study (PDF) done by researchers at the University of Michigan and HP labs provides insight into how big a performance penalty Zen pays and what causes the overheads (primarily L2 cache misses)." From the report: "We compare both technologies with a base system in terms of application performance, resource consumption, scalability, low-level system metrics like cache misses and virtualization-specific metrics like Domain-0 consumption in Xen. Our experiments indicate that the average response time can increase by over 400% in Xen and only a modest 100% in OpenVZ as the number of application instances grows from one to four... A similar trend is observed in CPU consumptions of virtual containers."

Once again, the stage was set for Sony to try to get some good will directed towards its next-gen console. Recent weeks especially have seen PR frustrations and setbacks for the company. Today was Sony's day to deliver: and in my opinion they did with flying colours. By the end of the keynote attendees were laughing and clapping with glee at the goodies that the company is going to be bringing to the PlayStation 3. Finally, finally, there seems to be a light at the end of the tunnel for the console. Read on for my notes on the keynote, as well as links to other coverage of the event. Note the first: There may finally be a great reason to buy a PlayStation.