last thing : what interface make and model and what did you do for video drivers

Corsair CMX4GX3M2A1600C8 2GB DIMM DDR3 PC3-12800U DDR3-1600 is 1.65v memory goto bios and manual set voltages and timmings !! stock ddr3 is 1.5v your board cant be stable unless you set it manualy..il look in tomorow

Here 3 files related to: 1-my system https://dl.dropbox.com/u/63155662/System.pdf 2-The system stat after all the bios and firmware upgrade and the tuning of Ram voltage.https://dl.dropbox.com/u/.../System%20stat%203.pdf 3-a quick time mov that shows the problem.https://dl.dropbox.com/u/63155662/My%20X2.mov Note that the quickfix was already present at the start of this thread.

Please: note also the behaviour of the track elipse points...

piangio: im questioning your os install ...given that your ram voltages were not set. how good can it be ?

I don't understand. How can I do it. Motherboard bios does not have any possibility to change the ram voltage values

But I also repeat that from the moment I purchased it, I worked hard on X1 without any problem. This began to happen at a certain moment without any reason (I didn't install anything but the windows updates and Airdisplay, now uninstalled)

Perhaps there are one or more services running in the background interfering with things?

Antivirus software? Unnecessary things like print spooling, IP helpers, other network stuff?

Sometimes 3rd-party plugins can also wreak havoc through non-standard coding (I have had some not precisely adhere to VST specs, for example).

I have also had cases where audio interface drivers are using non-standard code.  I just went through that about a month ago with a Presonus AudioBox 1818VSL. 

I have also had bizarre latency spikes caused by end-of-life laptop batteries, even though the laptop was on AC at the time.  Disconnecting the battery solved that.

Bottom line is that there are a number of unknowns with your system.  It has also taken a large number of threads to get a sense of what hardware and driver/bios versions you are running.  It would help if you were to list all of that stuff in a single posting in this thread, so that we could better have a handle on how to help you.

Also, there was an earlier post about Win7 x32 and memory - yes the 32-bit version can only reference 4GB of memory.  The x64 version can reference far more than any motherboard could possibly have installed.

Bob Bone

Sonar and its featured aplications is excluded from the routines of Karpersky and Win defender. Bob I don't understand, above all for my poor english, your last two lines about 32bit windows.

1.  32-bit XP can reference only 4 GB of memory
2.  64-bit Windows 7 can access 192 GB memory
3.  You need to go through a somewhat painful exercise of stopping things like antivirus programs and also services that are not used for audio processing sessions.  This will allow access to more memory, and will also potentially eliminate the kinds of dropout problems you are experiencing.  Things like print spooling, antivirus programs, and anything connected to IP processing or networking are NOT needed during audio processing sessions.  Sometimes antivirus programs (or others) DO interfere with audio processing applications, such as Sonar.  

PLEASE PLEASE PLEASE go through and turn things off, one at a time, on a temporary basis, to try to see if anything per item 3 above is contributing to your audio dropouts.  If you find something that is, you have to either work around it, temporarily disable it during audio sessions, or permanently disable it.

If you find nothing on your system is interfering in any way, shape, or form, THEN you may have exposed some sort of bug within Sonar, although it STILL could be at that point an issue with your audio interface drivers, some unneeded but present hardware device (parallel port), or a bios/chip-set issue.

Nobody can help you with this set of issues if you haven't exhausted the above possibilities.

Lastly, can your system be upgraded to the 64-bit Windows 7?  I was a DIE-HARD fan of XP Pro, but Windows 7 is ABSOLUTELY a better OS.  That is also something for you to explore.

Please respond to the above points, 

Bob Bone