[ntp:hackers] Windows 8 has a microsecond-precision system clock

Dave Hart hart at ntp.org
Sun Mar 4 12:40:11 UTC 2012


On Sat, Mar 3, 2012 at 16:48, Terje Mathisen <terje at tmsw.no> wrote:
> Dave Hart wrote:
>> I don't have Win8 installed yet.  I was just investigating installing
>> it in a .vhd as an alternate boot option, to test:
>>
>> http://www.davehart.net/ntp/win/win8-precise-time/ntpd-4.2.7p262-win8-precisetime-debug-bin.zip
>
> I'm pretty sure that if you run Win8 in a virtual machine, you'll see the
> time resolution of the virtual host, not the Win8 improvements.
>
> (This is unless you allocate a single cpu/core, causing Win8 to use RDTSC,
> and then get VMware (or your vm host) to assign the client process to a
> single cpu for the duration: In that case it should be possible to get
> real-world timing accuracy.)

The mention of .vhd (virtual hard disk) threw you off a bit -- I
wasn't considering running Win8 in a VM, though I was planning to
install it inside a .vhd file on my existing NTFS filesystem.  Since
Windows 7, there has been support for booting Windows installed in a
.vhd on unvirtualized hardware.

http://www.howtogeek.com/75286/how-to-dual-boot-windows-7-and-8-without-re-partitioning-using-vhd/

Cheers,
Dave Hart


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