Hi there:)
 
Constellation: Intel Core i5 2500 3,3 GHz with RME HDSP 9652
 
I've made a fresh Partition with Win 8.1. newest drivers for Graphics, Audio, Lan etc...
Old Partition with Win 7, newest drivers for Win 7!
 
Now I started "Latency Checker", and both Windows are OK, at about (Yellow) 1000 µs , but mor stable in Windows 8.1, in win 7 there are some Peaks, but not bad.
So far so good, if I start Sonar and any Project, the Performance of Win 7 is much better than in Win 8.1, the CPU View shows it double as high as in Win 7!!! Why?? Same PC, same Audio Card, newest drivers and the "Latency Checker" and the "Latency Mon" both mean that it is OK!!!
 
Any Ideas?? Any Win Services I have to throw out in Win 8.1??
 
Thanks;)
Basie

Under performance options make sure you optimize "processor scheduling" for programs NOT background services.
Check to see if you are running antivirus (always a good idea to run antivirus, please don't disable it, just make sure you exclude folders relevant to your DAW).


You might think you are up to date with drivers but running this has proven me wrong on many occasions:
http://forum.cakewalk.com/Driver-Boost-m2928792.aspx
 
Also check this:
http://forum.cakewalk.com/Todays-windows-optimization-tip-m2935172.aspx

This might be very useful to you:
http://technet.microsoft.com/en-gb/sysinternals/bb896653.aspx
 
When running please enable show details for all processes.

Don't forget to run windows update everywhere and defrag.
 
Remember occasionally you are swapping performance out for stability (with todays processor power we often have the luxury to use it elsewhere when it is useful). 
 
Cheers...

CakeAlexS
Under performance options make sure you optimize "processor scheduling" for programs NOT background services.

 
Hello Alex,
I have read posts with the same notice (including a post from Noël Borwick).
But i am a little irresolute, because the manual of my audio interface (Roland UA-101) recommands to give the priority to background services.
What do you think about that ?
Thanks you.

A myth, keep the defaults is my advise: http://forum.cakewalk.com/Priority-Programs-vs-Background-Services-m2303789.aspx
 

 
Thanks you for the advice and the link.
I think i will change my settings this way (it's seems logical, as Sonar is surely not a "background service").

Hi Basie,
as you can read here http://www.thesycon.de/eng/latency_check.shtml latency checker did not display proper results under Windows 8.x
Only latencymon http://www.resplendence.com/latencymon can do this. So please run latencymon on both OS. Relevant is the highest reported DPC Routine execution time.

You might also consider checking your Power Management options in both Windows 7 and Windows 8.
 
I use the High-Performance power plan, and further adjust a couple of things in the advanced options.
 
1.  I make sure to turn off the Selective Disabling of Idle USB devices.  (My audio interface and/or midi controllers would otherwise get disconnected after some period of time).
 
2.  I also always make sure to change the Minimum Processor State to be at 100%, meaning I fix the CPU performance at its maximum.
 
3.  I actually don't bother with tweaking my antivirus software, as my performance is fine even with it running and not excluding folders and such, but lots of folks do add exclusions to their antivirus software.  Some folks suspend antivirus software when running Sonar sessions.  (I use Avast's free version - I DO suspend it when downloading Sonar updates/upgrades).
 
Bob Bone
 

The DPC  Latency Checker is invalid for Win 8 (unless they have finally published the new compatible version in the last couple of days). 
 
I don't know how to compare but I don't really see any difference between Win 7 64 bit/Sonar X3 and Win 8.1 64 bit/Sonar X3.  That is on the same hardware with a dual boot system (i7 3770 CPU, 16GB RAM).  I'm seriously considering moving my "production" to 8.1.  I've been checking all my add-ons, hardware, etc and all of it works in 8.1.
 
 

Quite interesting. Id sure consider it unto my next build ;)

 
Something curious : when i check my system (Win 7 / 64) with DPC (dpclat.exe), it indicates ther is no problem for audio,
but when i run  Latencymon it indicates a problem (hard pagefault).