I though I'd share something with people in case they are interested.
 
I discovered today that Windows accidentally disabled the device in device manager -> System Devices -> High Precision Event Timer.
Apparently this is quite a common problem, I confirmed it shouldn't have been disabled in my case because I have two other windows partitions on the same PC which had it enabled. So I was running my Windows DAW off the software timer rather than the hardware timer on the motherboard.

Once I enabled it, it made a massive difference.

Should you decide to enable it (do so entirely at your own risk):
1) Make sure it isn't already enabled.
2) Make sure your motherboard is capable (most modern motherboards are). Note there was no setting in my BIOS for it (hard coded obviously), but that's where you should check first.
3) Backup!
4) Follow these instructions:
http://www.ghacks.net/2013/04/18/try-changing-hpet-settings-to-improve-your-pcs-performance/
 
Background here:
http://en.wikipedia.org/wiki/High_Precision_Event_Timer

Doktor Avalanche
....
Once I enabled it, it made a massive difference.....

In what way?  (Not doubting you.  Just curious, as I've never heard of this before).
 
BTW, thanks for the tip.

Interesting. I can see I have it, and have it enabled, but I don't know yet whether I've forced Windows to use only that. Based on a quick google, doing the rest but failing to do that step can make performance worse. Must have a tinker.

John T
Interesting. I can see I have it, and have it enabled, but I don't know yet whether I've forced Windows to use only that. Based on a quick google, doing the rest but failing to do that step can make performance worse. Must have a tinker.

Please define "that step"?

Forcing windows to use only that timer. Apparently it can use a combination of timer methods, but that's seemingly not a good idea, at least based on a very quick read-up.

Aha. Thx.

Be careful on this one, but not for the reason you might think.
 
I discovered this a year or so back, but instead of changing the standard boot profile, I added a second one with HPET enabled, which allowed me to toggle between the two (for testing and just in case reasons).
 
There was a recent (last couple of months) Windows update that failed horribly on "dual boots": it won't install and caused a stream of reboots to fix itself that had me gritting my teeth in terror.
 
KB3033929 I think is the Windows patch reference.

Well, I had it on in the BIOS, but Windows wasn't set to use it. I've got it active now. Will see how it pans out.

KPerry
Be careful on this one, but not for the reason you might think.
 
I discovered this a year or so back, but instead of changing the standard boot profile, I added a second one with HPET enabled, which allowed me to toggle between the two (for testing and just in case reasons).
 
There was a recent (last couple of months) Windows update that failed horribly on "dual boots": it won't install and caused a stream of reboots to fix itself that had me gritting my teeth in terror.
 
KB3033929 I think is the Windows patch reference.

Which version of Windows? I'm on my phone so can't see if you have it in your signature; sorry.

Windows 7 SP1 x64.