[Resolved] Multi CPU Kernel/HAL for Windows XP

[Fozzie Bear]

I have been using Virtual Machines on OSX using Parallels and Fusion with newer Windows versions (8.1 & 10) but fairly new to Virtual Box configuration for older OS's.
The scenario I am trying to establish for a customer is to run Cad/CAM software on Windows XP 32 bit as a virtual machine on a i5 Processor based Windows 10 Host PC. This is the only workaround for CNC machines that communicate by netbui network protocol and XP is the last windows OS to support this.
I have this running on a similar machine in another customers factory and it works well however I had to change the machine settings from One CPU to Two CPU's to overcome some performance issues. As far as I am aware the Cad/Cam software is NOT multi threaded but the change definitely resolved the issue where files took several minutes to open.

My questions relate to switching from a single CPU to Two CPU's in the Machine settings. I expected to have to make a registry change in XP to support the extra CPU but it just seems to boot normally and shows two CPU's in Device Manager. Does XP install a multi CPU driver on reboot? Normally I would see the normal "new hardware found installing drivers" dialogue followed by "You need to reboot for Hardware to Work Properly" but don't see any of these installation warnings!

Perhaps I am getting confused with changing from normal to AHCI Mode which requires a registry hack or reinstall of the OS, but there are comments on these forums that confused me.
* The first is that XP only ever requires One CPU even though my own experience shows performance improvement with Two CPU's

* The next is that XP does not need or require I/O APIC enabled. This may be true for a single CPU but when changing to more than one CPU the settings show an incompatible configuration and automatically enables I/O APIC on exit.

* The third is that a reinstall of Win XP is required in order for both CPUs to become enabled in the OS is this true or false?

* Finally being graphics intensive I allocate 64mb Video Memory for the Cad/Cam software. Is this enough or should I allocate more memory 128Mb? (I am using the built in i5 CPU Intel UHD 630 Graphics of the host machine using HDMI to monitor).
Currently the highest resolution I can achieve with a full size window (Not full screen) is 1920 x 975 at 100% scaling rather than 1920 x 1080 which is the natural resolution of the monitors. The video settings in XP don't go higher than 1920x975. I am not sure how the machine Video settings allocate/share on board CPU Video memory and if this is why I cannot achieve 1920 x 1080 ?

Many thanks
Fozzie

[mpack]

In the XP guest, go to "My Computer | Device Manager | Computer" and observe what the driver is called.

If it says "Advanced Configuration and Power Interface (ACPI) PC", it means that XP was installed with a single CPU HAL. It takes more than a registry hack to fix this!

If it says "ACPI Multiprocessor PC"... , well the meaning is self evident.

Below is a discussion containing instructions for converting an existing XP install to a multiprocessor HAL. Obviously you should back up the VM first.
viewtopic.php?f=1&t=24823&start=15

[BillG]

The vm does not share the host's graphics card at all. It uses its own (emulated) video card. For this reason vms are not a good way to run a program which is graphics intensive.

I always install XP with 2 CPUs so it installs the multi CPU HAL.

The difference in video resolution is probably because of the requirements of the VirtualBox window (menus at the to and icons at the bottom) . You would need to switch to full screen (from the view tab or Host+F control key).

[Fozzie Bear]

In the XP guest, go to "My Computer | Device Manager | Computer" and observe what the driver is called.

If it says "Advanced Configuration and Power Interface (ACPI) PC", it means that XP was installed with a single CPU HAL. It takes more than a registry hack to fix this!

If it says "ACPI Multiprocessor PC"... , well the meaning is self evident.

Many thanks mpack . I went back to the two machines I'd built and the one I changed from 1 xCPU to 2x CPU after installation still displayed "Advanced Configuration and Power Interface (ACPI) PC" whilst the other where I changed the machine settings to 2 x CPU before installation clearly showed "ACPI Multiprocessor PC". so had installed correctly.

Thanks for the link to changing the HAL post install, but decided it was easier and quicker to reinstall from scratch.
Thanks again I have learned something elese about XP and Virtual Box.
Fozzie

[Fozzie Bear]

The vm does not share the host's graphics card at all. It uses its own (emulated) video card. For this reason vms are not a good way to run a program which is graphics intensive.

I always install XP with 2 CPUs so it installs the multi CPU HAL.

The difference in video resolution is probably because of the requirements of the VirtualBox window (menus at the to and icons at the bottom) . You would need to switch to full screen (from the view tab or Host+F control key).

Thanks for your reply BillG,
I did consider the toolbar may be affecting the vertical resolution. To be honest its really not a big deal and the operators prefer to use a window rather than full screen view so they can easily access the host machine desktop.

I wasn't aware that Virtualbox uses emulation for Video but was aware that Virtual machines aren't the best option for Graphics intensive software like Cad or Video Games.

Having to use an unsupported OS like XP in order to communicate with the CNC machines has forced this customer and many other CNC operators down this route of using a virtual machine. To replace the CNC machines or their controllers would cost hundreds of thousands of pounds which they cannot afford in this climate. This option also gives them a way to run the Cad software whilst running an up to date host machine for everything else like Office 365, OneDrive and Antivirus non of which install on XP.

Thanks again for your reply
Fozzie

[socratis]

but decided it was easier and quicker to reinstall from scratch.

That's what I usually do as well. It's best if you start fresh, with the correct settings, rather than trying to "patch" an existing installation. Especially for older OSes, where Plug'n'Play was an unknown term.

Marking as [Resolved].