New Machine - Sonar 5/Sonar 8 - SAME PERFORMANCE???

Can anyone explain to me WHY....
 
Sonar 5 on XP 32bit.
Sonar 8.5 on Win7 64bit.
 
Over the weekend, I installed them back to back on the same machine.  First, the Win7/SPE 8.5.  Then, formatted and installed the XP/SPE 5.
 
In both cases, I loaded up the same exact mix - with the same exact plugins.  Both installs performed rock solid.
 
Same exact CPU hit.
 
Doesn't seem right....especially since every update for as long as I can recall has listed "audio engine improvements" as one of the reasons we should be upgrading.
 
Apples to apples, it seems that the only thing I've been upgrading over the years has been on the hardware side.
 
Now...granted....I'm probably not the "average user".  I only use Sonar as a digital tape machine...and I mix with it.  I don't use ANY of the soft-synths....and I really don't care how flashy the user interface is.  In fact, Sonar 5 has been my choice for years because of the GUI.  It works for me...and the Sonar 6 and 8.5 versions I upgraded to simply sit in the closet.
 
I'm just sort of shocked that a 10 year old version on a 10 year old 32 bit OS runs as fast as a NEW version does on a NEW 64 bit OS.

I'm sure there are a lot of things to consider.  I'm sure many, many more than I could ever understand in bios settings and hardware choices....

And of course I could set up a "stress test".  But what's a better stress test; some sort of "hypothetical" test with tracks that are unprocessed, or a real-world test - where you're using real tracks with the actual plugins you're going to be using in your normal work flow?  I would suggest the latter, as those results are really what matters to a user who just needs the system to work, as efficiently as possible, every time.

Are you suggesting that maybe these particular plugins are what limits Sonar to a certain throughput, regardless of release version or OS?  And that if I were to simply run unprocessed tracks, Sonar 8.5 on Win7 would run more tracks than Sonar 5 on XP?  Again, if that indeed were the case, I'm not sure why it would matter to a guy who actually is going to use the system with plugins.

Don't get me wrong...I'm not really complaining about Sonar/Cakewalk.  I'm a Cakewalk guy...and have been since about 1995.  And I'm not trying to argue...because, in the end it doesn't really matter since this new system is murdering my last one...and I was already a pretty happy camper.  I built my dual Xeon system about 5 years ago and it's still a monster in practice.  I'm sure I'd still be using it 5 years from now if I needed to.  But this new i970 with the SSD's is frikkin' insane!

LOL...if that's the case, then absolutely, make sure you include them in the GUI.

That's what I'm saying, Frank.

I DO have Sonar 5.xx on the new machine with XP-32bit, and it performs exactly the same as 8.5 did on the new machine with Win7-64bit.

I wish I had that $150 back for the dang OEM version of Win7.