Perhaps I don't fully understand what the "64 bit double precision engine" checkbox in preferences really does.
If I'm running Windows 64 bit, and Sonar 64 bit, wouldn't I always want it on ?
 
From reading some of the information Cakewalk has on their website about this:
 
^{"The 64-bit Double Precision Engine provides greater resolution, meaning more accurate audio reproduction and more headroom. You'll especially notice the benefits of the 64-bit Double Precision Engine when working in large projects containing many audio tracks and plugs-ins. Your chances of clipping will be significantly reduced."}
It's what we all want.
I also wonder why when I first installed Sonar X2-64 bit, the default setting was to have it turned off ?
 
When I export my 24 bit recorded project to 16 bit CD audio, there it is again, an option to turn on or off the "64 bit double precision engine"
I guess it's asking me to choose whether I want to include the 64 bit engine in my mixdown, but I'm not sure, because I can't hear a difference.
 
When I was running Sonar X1 on my 32 bit system, the "64 bit double precision engine" was still an option to turn on or off.
 
Is anyone out there just leaving it on all the time, or off all the time ?
 

I leave it on all the time.

Using it means there will be less rounding errors when converting from a floating point file (which is what Sonar natively works in) to a fixed point format, such as the 126 bit for CD's

One thing I noticed was that the 64 bit plug ins then indicated correctly that they were 64bit... two dots underlining them when the box is ticked.

Cheers.

Id leave it on.

on unless you are troubleshooting a problem.

It's an option because it consumes more processing power. But these days, most people have plenty of PC horsepower, so leaving it on isn't a problem.

Scott

--
Scott R. Garrigus - http://garrigus.com
* Author of the Cakewalk Sonar and Sony Sound Forge Power book series: http://garrigus.com/?PowerBooks
* Author of the Cakewalk Sonar ProAudioTutor video tutorial series: http://garrigus.com/?ProAudioTutor
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Isn't it only of benefit "ON" when you Bounce or export?

It just does internal mathematical calculations with more precision (64 bits instead of 32) and is different from the 64 bit OS or SW versions, which involve memory addressing instead of calculations.

As a general idea, you can think of it in terms of dividing 10/6 and the result is 1.666666667 instead of 1.67.

But in reality (despite what some people's imagination tells them) 32bit single precision floating point already puts calculation errors far below ever being audible, so whether you turn it on or not doesn't really matter. And it has no effect on whether or not plugins use 32 bits  or 64 bits internally (programmers use what is needed when it is appropriate - 64 bit calculation becomes important for things like recursive processing, but not for simple adding or multiplying).

And the statement that, "Your chances of clipping will be significantly reduced", though technically correct, is particularly humorous in that 32 bits already provides hundreds of dB's of headroom over 0dBFS when in the real world no one ever goes more than a few dB's above 0dB (either by accident or when they're intentionally trying to distort something). But it does show that this is intended to impress people who don't understand math rather than provide any practical benefit. 

why people STILL and always confuse a wordlenght in summing with the bit resolution of a programcode ???

the first is pure audiosumming mathematics the other is related to how a software can (just one example) adress memory 

totally two pair of shoes

I have it off (I think) for normal use but turn it on for export or bounce. no reason other than I'd completely forgotten about it.