WinXP SMP still VERY SLOW under VB 4.3.6

[socratis]

Actually I went back as far as 2.2.4. Installed a plain vanilla XP without IO/APIC (let call it "No") and one twin XP with IO/APIC (let's call it "Yes"). Nothing else enabled. The No installation was consistently faster compared to the Yes (~70%). I then enabled IO/APIC to the No guest and there was no change. At all. So it is NOT the IO/APIC in VBox. It is the difference in the Device Manager -> Computer, ACPI implementation of WinXP. Note that I did not increase the number of processors. Both single CPU.

I cannot verify on real hardware if changing the "driver" in the device manager causes that as well. But after an extensive multi-day research, I'm inclined to say that this may not be after all a VBox issue, but a WinXP issue. At best (worst) it could be the interaction between the ACPI setting in WinXP and VBox. I have no clues about that, nor do I want to speculate.

[thanar]

At best (worst) it could be the interaction between the ACPI setting in WinXP and VBox. I have no clues about that, nor do I want to speculate.

If I was to speculate, I'd say that this should be the case, since having a multi-CPU winXP VM with ACPI setting doesn't drop performance in a Parallels Desktop setup, and winXP sees all 4 CPUs as expected.

[socratis]

So if you compare two 1-CPU WinXP VMs in Parallels, one where the computer property for ACPI has been modified in the Device Manager and one that has not, you do not see any differences?

[thanar]

Will try it and let you know. I suspect there will be no difference, since the same zip file takes around 1% longer to uncompress in Parallels VM when compairing VirtualBox VM with 1 CPU and Parallels VM with 4 CPUs. The Parallels VM has a few extra software (including antivirus software) which explains the slight delay I guess.