Back in the day we had to tweak Windows XP for Sonar. Is that still neccessary with Windows 8 & X3c? I'm having issues with my audio and my engine being stopped for some reason everytime I hit play. these projects played in Sonar 6 & Sonar X2. Just trying to find the root of this evil.

You might do better titling this thread: audio engine stops every time I hit play
 
Many people are running Sonar under Windows 8 without "tweaks" which generally refers to changing system settings to optimize performance. What is stopping your audio engine is not a lack of tweaks.

To answer your question;

No tweaks are needed with Win8.

I would do like slartabart suggests. Give us more info about your system /project to see if we can help find out why you get the AE stopping.

Ok, so any suggestions as to what it may be? I titled this thread in the form of a question because I'm asking the question. I know what tweaking the system is as stated above I did it years ago with XP. What I need to know is will that improve my PC's performance and help solve that particular issue? Any helpful suggestions would be greatly appreciated. Would also appreciate tips on tweaking Windows 8 if there are any that significantly help improve Sonars performance.

Thanks in advance

Thanks Grem, 

Well to start I loaded a project I originally recorded in Sonar 6PE, loaded and re-saved into X2 I just upgraded to X3 and tried to play the project there and that's when it started. Also am getting no sound from my soft synths in another project that was working in X2. Not sure if that is related just throwing it out there incase some connects the 2 issues.
 

Did you perform the recommended reset/rescan after installing X3? http://www.cakewalk.com/S...reader.aspx/2007013315

Thanks for replying. Yes I did. I've actually done it atleast twice since installing

Did you check the 32 versus 64 bit list of your plugs? Buffer size adjustment for latency and dropouts? In addition, disabling a few USB's, network card and ensure compatibility of your video card helps. 
I wish you luck in finding the root cause and fixing it asap. 
 

Is disabling USB hubs really necessary? I read somewhere that turning off each USB hub's power management option (Control Panel > System > Device Manager > USB Root Hub > Properties > Power Management > Allow the computer to turn off this device to save power) would suffice. I did it this way and it cleared up a frustratingly hard-to-find problem I was having with my Privia keyboard.

I am a bit unclear on a couple of things:
 
1.  Are X2 and any other prior versions of Sonar also installed on the same computer that is running X3c under Windows 8?
 
2.  It looks like the latest drivers for the FireWire 800 came out in November of this year.  Are you running with this version?  It also indicates that for this version to run correctly that you need to update the firmware, as well.
 
This is the text snippet from the downloads page for your FireWire 800 interface:
 
"Windows 7/8 32/64 bit PnP driver for Fireface 400, 800, UCX, UFX, version 3.081. Requires the latest firmware version! 11/22/2013"
 
3.  Do you have all Windows 8 maintenance applied?
 
4.  You have multiple interfaces listed.  Which one are you using?
 
5.  Are you using ASIO as your Sonar Driver Mode?
 
6.  What happens if you create a new project in X3c, with some 64-bit soft synths and perhaps some audio?  (does it also stop playing?)
 
At first GUESS, I would imagine there to be some issues from 32-bit plugins present in these older projects, where something slightly different in X3c is exposing an issue with one or more of those 32-bit plugins, causing your issues.
 
It seems to me that there have been a pretty good number of threads where one or more 32-bit plugin has had trouble in some version of 64-bit Sonar.
 
Many folks have moved to limit or even eliminate use of 32-bit plugins in a 64-bit Sonar installation.  
 
I have made a deliberate choice to ONLY allow a small number of 32-bit plugins to be even present in the search path for 64-bit Sonar (X1d, X2a, and X3c).  I DO keep 32-bit versions of all 3 of those Sonar releases, and those have access to all of my 32-bit plugins.
 
On my system, running as above, I have no issues such as you are having.
 
Perhaps you could do some experimenting with either swapping out your 32-bit plugs for 64-bit ones, or work in a 32-bit install of X3c, or finish those projects in X2a, and move to either limit or eliminate 32-plugins moving forward.
 
Bob Bone