Studio Instruments is also one that (at one time) didn't like X-Ray which I thought was odd because it was a Cakewalk product.  A CW tech told me to disable X-Ray (BTW.)

Good observation, but no it's well below peaking. I tried few patches to see if that mattered but it was still noisy with clicks. If I freeze it the noise goes away. Like I said, this is the first time I've had to freeze a synth so I was surprised. I only use the SI-Bass as a quick placeholder until I record the real bass so it's not that big of a deal now that I've narrowed it down to that. I've have to experiment to see if it's just that synth or if impacts others as well.
 
btw, on your comment a FW card... when I first got the ProFire 2626 it would not work properly with my computer's on-board firewire so I had to get a dedicated card.

Mod Bod
Studio Instruments is also one that (at one time) didn't like X-Ray which I thought was odd because it was a Cakewalk product.  A CW tech told me to disable X-Ray (BTW.)

Thanks, Dave. I've never even used X-ray so thanks for reminding me to turn it off.

Probably the plugin as you say, but you could try disabling Intel Speedstep in BIOS.

Strange. SI stuff is really lightweight. Does it matter whether the GUI is open?

> Probably the plugin as you say, but you could try disabling Intel Speedstep in BIOS.
Oh and you have rescanned the plugins right?

CakeAlexS
> Probably the plugin as you say, but you could try disabling Intel Speedstep in BIOS.
Oh and you have rescanned the plugins right?

I rescanned when I first loaded X3, but I'll do it again.

Laptop?
WIFI can be brutal on audio perf.
 
This utility is really good for telling it like it is on a particular system (even if not a laptop)
 
http://www.resplendence.com/latencymon

Nope, not a laptop and no wi-fi.

DesertHermit
Nope, not a laptop and no wi-fi.

Still worth running the utility.  It will show if system drivers are taking too long to do something.  
Sometimes background processes can contribute to the overhead as well.  It can take some detective work to figure out what to do based on the report, but at least it will give you a starting point.