Abstract: Some notes on trying to run Windows 2003 Server EE on Amazon EC2 extralarge type of instances (4 way).
I tried to use Qemu's -smp n feature on Amazon Elastic Compute Cloud, but it still uses only one processor. It is possible to set affinity and run each Qemu instance on individual processor, but this is very nontypical scenario. Also this article explains Qemu's "rdtsc" usage on SMP hosts http://lists.gnu.org/archive/html/qemu-devel/2007-03/msg00652.html
Moving system disk to RAM decreased disk-related IO by 10-15%, but CPU-bound bottleneck still slowed system down.
Windows Device Manager showed that our installation uses MP kernel according to "ACPI Multiprocessor PC", ACPI APIC MP HAL (Halmacpi.dll).
I'll keep you informed on my other findings.