Just went back into my power management settings again and this time it said '100%' so I may have accidentally been looking at the 'power save option' (5%) before. It says I have 'High performance' active.

If you go the USB interface route use a port that is directly on the motherboard (not the front panel of the case or through a hub) and make sure you always use that port after you have installed the drivers. If you want to move it uninstall the drivers and reinstall them with the unit connected to the new port. Be sure to use the correct type of port. Most modern USB interfaces are USB 2.0 to so be sure to use a 2.0 port, not a 3.0 or 1.0 (if those even still exist).
 
If you happen to get a chance also ask Rain whether your PCI slot is Bridged or Native (I'm curious). Also ask them if your Firewire connections use the audio recommended Texas Instruments chipset. Without one of those chipsets Firewire devices tend to have problems. I say this because if you ever decide to hook up a firewire interface if it DOESN'T have the chipset be sure to purchase a PCIe firewire card that does have the chipset to avoid problems. These are just things to know about your system to give you a bit more knowledge and insight as to what your system is capable of.
 
As far as RAID they may have set one up for you when they built the system. If they did you'll have more than the usual 2-3 hardrives on your computer. It's just a redundancy set up so if a drive fails the data is still on the other drives and I think it allows for faster data retrieval. It's a pretty high end type of feature but it is certainly not uncommon on fancy audio builds. Just ask them and they'll be able to tell you. If there is a RAID set up I'm jealous. ;-)
 
Oh and if you do end up replacing your interface for something more modern you could also get a PCIe based soundcard. PCIe doesn't have the same problems as the legacy PCI stuff and, in theory, is faster than USB. USB 2.0 however is more than fast enough for streaming audio. I just mentioned it because it gives you more options while choosing a new interface and there are some very high quality PCIe cards out there.
 
I'm not a computer tech though so make sure you do a lot of research and ask a lot of questions from pros like the guys at Rain.
 
Cheers.

Just an update for you all...
 
Tonight the problem has returned! But after a while of not really doing anything other than adding synths to a test project and tweaking the Pro Channel EQ - it has stopped.
I have checked MIDI tracks vs Audio tracks - at first it looked as though it might have been the audio tracks that caused the worst problem - but then the issue vanished completely.
 
Tonight it seems like a strange latency has joined in the fun. The audio 'over runs' and motor boats/pops when I start and stop playback. That's new.
 
RAIN assure me that they made every 'tweak' an audio PC could ever want and that nothing is running in the background that could be causing an issue. He is still gonna dial into my PC hopefully this week to see again for himself.
 
What the hell is going on. This has been going on for months and months.

...Can I also just bring this to the table again: Home Studio 7 runs PERFECTLY. It just feels completely solid. What does this eliminate?? Does this mean my SOUND CARD is not a culprit? Does this mean my SYSTEM is not a culprit? Does this mean DRIVERS aren't culprits?
 
Could it be a 32/64 bit issue? I believe Home Studio is a 32 bit programme? I don't even know what I mean by this, but hey.
 
Could it actually just be a bad install of Sonar X2? (I have never tried a re-install of Sonar X2)
 
If I should try the latter - could you give me a couple of pointers about how to uninstall properly? (I have read volumes about this but never quite understood it. Plus the diving into the registry bits frighten me.)
 
Thank you.
Dave

Dave,
 
When you faced the issue, did you launch LatencyMon and see what was happening? That is definitely the tool that can point you to the problem.
 
Edit: Well it aught to be able to. hmmm feels all insecure suddenly. ;-)

Have you tried deleting Sonars Aud.ini file?

I have just noticed that when I start or stop a Windows Media player video, I get pops.
Is this telling me something?
 
thebiglongy: I've seen that mentioned lots but never understood what it's for?

It's Sonar's initialization file.
 
If there's one already on your system, installing Sonar will append whatever it thinks is necessary.
 
If you delete it, Sonar will build a new one based on your current settings and this has solved a number of problems in the past.
 
Try it. If you're worried something might happen and you want to revert to the old one, just rename it rather than deleting it.

Silicon Audio
There is a huge clue in your report.  You have your CPU dynamically changing speed.  This is often the type of thing that can cause your problem.  You need to sort this out first.  As I have said previously in this thread, at the very least, you should go into advanced power settings and set the minimum processor state to 100%

_________________________________________________________________________________________________________
CPU SPEED
_________________________________________________________________________________________________________
Reported CPU speed:                                   3500.0 MHz
Measured CPU speed:                                   2843.0 MHz (approx.)

Note: reported execution times may be calculated based on a fixed reported CPU speed. Disable variable speed settings like Intel Speed Step and AMD Cool N Quiet in the BIOS setup for more accurate results.

There are also guides on the internet about disabling speed step, etc.

+1 if this hasn't been handled already...

Silicon Audio
Disable variable speed settings like Intel Speed Step and AMD Cool N Quiet in the BIOS setup for more accurate results.

 
What affect might this have on fan noise ?  If you set your CPU to run full blast all the time, won't it run hot ?