Abnormal CPU Usage

Fubar · Post by **Fubar** » 12. Nov 2008, 22:06

The guest OS has 5 gigs of hard drive space, i've tried 128 and 256 MB of ram, I've tried an installation with ACPI off and on and still no luck.

My Host OS is i belive a 3.4 GHZ 64 bit AMD processor, 1 gig of ram, 100+ gig hard drive.

I'm running XP Professional with a guest OS of xp professional. My Host OS and guest OS cpu's both spike to 100 percent when for example i use IE. My host and Guest OS cpu's both get high spikes when i do just about anything. Just out of curiousity, i tried using Microsoft Virtual PC 2007 PS1 and VMware with the same end result. I've also tried using W2K which also had the same end result.

Please indicate if there are any types of logs that might prove useful and i will post them once i'm @ my computer.

Thanks in advance.

Post by **sej7278** » 12. Nov 2008, 23:32

100% cpu is on this forum a lot, sun have never addressed it for some reason.

there's one kludge that might help - use a 32-bit xp instead of xp64 and replace the acpi kernel with the "standard pc" kernel.

64-bit guest support sucks as a rule in virtualbox with any os (mainly solaris and xp).

Fubar · Post by **Fubar** » 13. Nov 2008, 00:12

the majority of the posts i read had Linux involved as far as the CPU consumptions go. I think it may be a hardware issue because i'm getting the same outcome on 3 different Virtual Machine Applications.

Post by **sej7278** » 13. Nov 2008, 00:30

1gb ram is really pushing it for running a guest and host os, its probably pagefile access thats slowing things down.

xp64 is a bit of a naff host let alone guest for virtualisation. with xp64 there is no fix like there is with xp32.

linux i'd say is the best host, and win2003 the best guest.

the only time i've seen high cpu load on a linux guest is with rhel4, but that's easily fixed with divider=10 kernel param in grub.

but 64-bit guest support seems to be rubbish overall.

Fubar · Post by **Fubar** » 13. Nov 2008, 00:36

Thanks for the responses.

I forgot to clarify that i'm not running xp64 bit edition. I was just describing the hardware. I'm running xp32 bit for host and guest. I purchased 2 gigs of memory to see if that will fix the issue.

Post by **TerryE** » 13. Nov 2008, 12:28

Fubar, welcome to our forum BTW. Have a browse of the FPG (URL below). I've posted on this before. If the guest code wants to run the CPU flat out then on your host the VMM will run at 100%. This isn't the fault of VBox, it's the flawed guest configuration. To get the guest process running at a few% when guest is "idling", the guest OS kernel must put its virtual CPU into a suspend mode when in its null process. The most common reason for not doing so is SMP synchronisation, but also some device drivers are pretty antisocial in this regard and use the RTC heavily.

So make sure that you are running a non-SMP version of the NT kernel as sej7278 says and also go around all of your main devices temporarily disabling their drivers in device manager to see if this causes a step drop in observed CPU. You can get XP VMs which will tick at less than 10%; it's just a lot harder to do this when you've done a P2V.