2CPU vs 1CPU performance hit for XP guest

[mfeller]

I am seeing a huge performance hit for running a Windows XP guest with 2 CPU's + IO-APIC enabled vs.1 CPU and no IO-APIC. Just a quick test, boot time for the 1 CPU guest is close to 30 seconds. Boot time for the 2 CPU guest is close to 2 minutes. I didn't time the install times, but it was much faster on the 1 CPU guest. As a guess, something like 15 minutes vs. 30 minutes for the 2 CPU guest.

Is this typical? Is the behavior the same for Linux and other hosts for 1 CPU vs. 2 CPU?

That was just some quick benchmarking. When I have time, I will try a few others.

System info: AMD Phenom 945, 8 GB RAM, 7200 RPM SATA disk, Xubuntu 64-bit as host OS
Both XP guests are 32-bit, 2GB RAM, 32MB video RAM, fresh installations. After installing the 2CPU guest and seeing how slow it was, I created and installed the 1CPU guest, trying to go through the same installation procedure. (I think the only difference is that I selected quick format for the disk on the 1CPU guest vs. the other option for the 2CPU guest)

Thanks!

[Sasquatch]

It is known that the performance isn't what it supposed to be. The feature is new and still not fully developed. Expect improvements over the next releases, it should go a lot faster in the future.