id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host
6936,High CPU consumption for multi-processor Windows guests,Max Zinal,,"Our install is:
  - 8-core 2-processor x86-based server with Xeon E5335 CPUs, 32 Gbytes of RAM.
  - Debian/GNU Linux 5 (Lenny) as a host system
  - Windows XP Pro SP3 as a guest system

We tried the following VirtualBox releases, with the same results: 3.1.8, 3.2.2, 3.2.4

We get high CPU consumption on host (up to 80-120%, measured by top) even when our guest system is idle. The effect goes away when we switch the system to a single CPU and turn off IO APIC (and move to single-processor kernel, of course).

We do not see same effect with exactly the same virtual machine on a notebook with Intel Core i7 processor, running Windows 7. So this problem might be processor- or even operating system-specific.

One of the interesting side-effects is that even when CPU usage on guest is near maximum (we use 4-core guest. and all cores are pretty busy at boot time), the CPU usage on host is about 170-180%.

The whole problem makes it pretty hard to use VirtualBox on that server, so we are abandoning our plans to buy VBox license for that host (at least until we can find a workaround).",defect,closed,guest smp,VirtualBox 3.2.4,fixed,,,Windows,Linux