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virtualbox use only one core

Posted: 31. Jan 2010, 01:05
by chronek
Hello

Is any way to use more core than 1 by VB ? After setting 2 processors in settings still VB run like single threaded process and use only one core in my Windows 7 64bit ...
Im asking cause I using linux guest for encode video footage (for best quality, mencoder from git ,ffdshow from svn, x264 from git) , encoding can use more cores , but with single threaded limitation i cant use all power of cpu and sometimes encoding can take 11 hours (even if i try compile with optimizations, so many options with encode need time to process)

Mike

Re: virtualbox use only one core

Posted: 31. Jan 2010, 01:12
by Perryg
Turn hardware-v on in your bios

Re: virtualbox use only one core

Posted: 31. Jan 2010, 01:20
by chronek
hardware-V ? My VB windows showing VT-x enabled

Re: virtualbox use only one core

Posted: 31. Jan 2010, 01:34
by Perryg
Yeah but is it gray? Can you turn it on and off? Can you see two processors in the guest?
If so did you set the processors to 2 in the guest settings?

Re: virtualbox use only one core

Posted: 31. Jan 2010, 01:47
by chronek
[V] icon is not greyed out , and when i focus mouse on that it shows that VT-x/AMD-V is enabled :-/ I do not have any option about virtualization in bios (i use nootebook with simple bios options). Yes , i set 2 processoe in guest settings , when i do cat /proc/cpuinfo i can see processor 0 and processor 1 , so guest see 2 processors , but with taskbar on windows wirtualbox use max only 50% and only one cpu is 100% , second near 0%

Re: virtualbox use only one core

Posted: 31. Jan 2010, 01:55
by Perryg
On the XP guest look in the device manager and under computer do you have uniprocessor or multiprocessor ACPI?

Re: virtualbox use only one core

Posted: 31. Jan 2010, 02:35
by chronek
it took some time cause i had to install xp guest again ^^ , under computer i have : Advanced Configuration and Power Interface (ACPI) PC (but didnt install guest additions yet)

After installing guest addition the same, maybe cause it is sp1 , ill try install sp3

Re: virtualbox use only one core

Posted: 31. Jan 2010, 03:33
by MarkCranness
chronek wrote:Advanced Configuration and Power Interface (ACPI) PC
'Advanced Configuration and Power Interface (ACPI) PC' is a uniprocessor HAL (Hardware Abstraction Layer = CPU driver) and can only use one CPU.

Either: Enable IO APIC in VirtualBox AND re-install Windows XP again, OR

Set IO APIC to on in VirtualBox Settings>System>Motherboard, then use HALu to change the guest XP HAL, and change it to 'ACPI Multiprocessor PC' (easier and preferred).

My own experience (and others) is that VirtualBox does not handle SMP (Multiprocessor) VMs well: Often the host CPU goes to 100% for no reason, even when the guest is idle. Try it and see.

These HALs require IO APIC enabled and may have host CPU usage problems:
ACPI Multiprocessor PC (HALu=ACPI Multiproccesor PC)
ACPI Uniprocessor PC (HALu=ACPI Uniproccesor PC)

This HAL doesn't care about IO APIC and will not have host CPU usage problems:
Advanced Configuration and Power Interface (ACPI) PC (HALu=ACPI PC)

Only 'ACPI Multiprocessor PC' allows the Windows XP guest to use more than one CPU or core.

Re: virtualbox use only one core

Posted: 31. Jan 2010, 03:38
by chronek
Ok , ill try , but it means that i do mistake and install xp on default settings with one processor , maybe it is the same for linux ? (that distro have before virtualbox supported multicore, but compiled kernel many times and with multiprocessor support) First will try on xp

This program updated to ACPI Multiprocessor PC, and looks like working good - running prime95 with 2 threads on guest use 2 core on host , so windows success
But what about linux guest? Maybe i need something change in configuration or exclude/include in kernel?
lol after stop prime still VB uses 100% of cpu host , and with guest one core full ;-) - ok , solved , maybe restarting guest after that change was bad move , after restarting aplication all normally in windows, so i know now that virtualboxwith windows guest can utilize my both core , how can i do that my linux guest distro could utilize too?
Ok, ill try reinstall debian.