Hardware/system clock speed.

Discussions related to using VirtualBox on Windows hosts.
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john.doe
Posts: 76
Joined: 10. Feb 2009, 16:39
Primary OS: MS Windows 7
VBox Version: PUEL
Guest OSses: WinXP, Vista, 2003, 2008, various Linux distros and others

Hardware/system clock speed.

Post by john.doe »

Hi, to be honest I've never used VirtuaBox, but I'd like to know if this is possible to achieve.
I'd like to slow down (virtual) hardware or system clock speed by 10 or more times. So for example - 1 second in virtualboxed system is like 20 normal (real) seconds. Some scripts on websites use hardware clock to measure time so slowing down only the browser (with cheatengine or speedgear etc.) wont' help.

I'm looking for any software which will allow me to achieve that.

Thanks.
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Hardware/system clock speed.

Post by mpack »

Nope. VirtualBox is a hypervisor, not a simulator - so code runs natively on the host CPU, at whatever clock rate the host CPU uses.
privattomtom
Posts: 15
Joined: 23. Nov 2009, 11:19
Primary OS: MS Windows 7
VBox Version: PUEL
Guest OSses: ubuntu, windows xp 32bit
Location: Germany

Re: Hardware/system clock speed.

Post by privattomtom »

john.doe wrote:Hi, to be honest I've never used VirtuaBox, but I'd like to know if this is possible to achieve.
I'd like to slow down (virtual) hardware or system clock speed by 10 or more times. So for example - 1 second in virtualboxed system is like 20 normal (real) seconds. Some scripts on websites use hardware clock to measure time so slowing down only the browser (with cheatengine or speedgear etc.) wont' help.

I'm looking for any software which will allow me to achieve that.

Thanks.
VBoxManage controlvm -cpuexecutioncap
The cpuexecutioncap <1-100>: This operation controls how much cpu time a virtual CPU can use. A value of 50 implies a single virtual CPU can use up to 50% of a single host CPU.

VirtualBox Manual page 124
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Hardware/system clock speed.

Post by mpack »

privattomtom wrote:VBoxManage controlvm -cpuexecutioncap
Um... that doesn't change the clock speed. When the guest is given its time slice it will run at the full clock speed. The execution cap simply prevents a VM from hogging the CPU to the exclusion of other tasks (particularly host tasks). Timers should be unaffected.
john.doe
Posts: 76
Joined: 10. Feb 2009, 16:39
Primary OS: MS Windows 7
VBox Version: PUEL
Guest OSses: WinXP, Vista, 2003, 2008, various Linux distros and others

Re: Hardware/system clock speed.

Post by john.doe »

I see. Many of you here have some serious computer knowlegde, so i'd like to ask if you know any other way to achieve that?

Basically what I need is to reconfigure software clock (the one that OS uses, not the CMOS). I found out that it has some layers (OS itself use low layer software clock, and higher layer is for applications). But i couln't find any way how to get into that.

It also may be accessable in virtualized system (VMware?).

I will appreciate any help.
Perryg
Site Moderator
Posts: 34369
Joined: 6. Sep 2008, 22:55
Primary OS: Linux other
VBox Version: OSE self-compiled
Guest OSses: *NIX

Re: Hardware/system clock speed.

Post by Perryg »

Perhaps if you explained what this is for we could come up with an approach that will work.
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