Eventhough I have a powerful computer I struggle to get the 64 bit version of X3 stable.  What happens is that when I play with software synths like Dimension pro or IKM Multimedias Sampletank 3 sound suddenly gets distorted and system hangs and are closed down.  I dont have to have many tracks  - only open one Soft Synt and still this happens.  Loops tends to first go much faster and then distort and system closes down.  I have to start X3 again.
 
I use the Cakewalk VS100 and Carillion PC.
 
In order to set up system latency I use the test within X3.  
 
Any suggestions as to what may cause this ? And hopefully a way to fix it ?

Try a restore point to rule out an errant install of an offending app/driver.

Are you running X3e?
 

Your system specs say Windows 8.  If you're not on Win 8.1, I urge you to do the update. (It makes no sense to have everything else up to date, but the O.S. isn't).

Hi. All good advice here. If not done already, make sure everything is up to date.
All the best.

Yes - everything is updated to last Version.

tenfoot
Are you running X3e?
 

Yes - X3e is installed.

JonD
Your system specs say Windows 8.  If you're not on Win 8.1, I urge you to do the update. (It makes no sense to have everything else up to date, but the O.S. isn't).

OS is updated to newest Version.

Does your VS100 have Win8 drivers, or do you run it in compatability mode? Is the sample rate the same in SONAR and the VS100 panel? Maybe even try to uninstall (VS100) drivers, reboot, reinstall, reboot again?
Best of luck.

I will have to find a link to them, but there are some hot keys you can use to control/change the sample rate used by Dim Pro, Rapture, and Rapture Pro - so that they match the sample rate you have Sonar set to use.
 
Since I run Sonar set to a sample rate of 48000, I also have the above synths all set to also use 48000, rather than their default of 44.1, and that took care of issues for me with those synths.
 
In addition, IF you have any 3rd-party 32-bit plugins loaded into any of your 64-bit projects, these MIGHT be a cause for instability.  Most folks who have commented in posts about it have indicated that for them, MANY instability issues went away when they quit using 32-bit plugs in a 64-bit Sonar.  (Some folks have reported also seeing stability for 32-bit plugs improve on a case by case basis through the use of a commercially available bridging application for 32-bit plugs called JBridge, which seems to run around $20.
 
Bob Bone