"I'm running Logic X on the clean install I did for OS X.10 Yosemite. (About 30 hours of work.) Logic Pro X is working with perfect performance on my 2008 Mac Pro. (IIRC, Dual 2.8GHz Quad-Core Xeon.) So, don't know why someone else would get bad CPU performance on their Mac using Duet 2.
(Duet 2 not the issue per later comments/tests with it removed. He has a 3.1GHz quad-core i5 iMac.)

I have an Apogee Ensemble and a Duet 1. No CPU problems here. I'm sending screen shots of a song I'm working on with 33 stereo channel strips and 22 AUX tracks, using tons of plug-ins and I'm showing very low CPU usage on this relatively huge song.
- John"

Thanks John. It may not have helped him but I'd forgotten about an apple doc I'd included in some support doc updates about Logic Pro X Processing Threads setting and Core Usage.
(Murray later wrote he's reverted back to OS X 10.9.5.)
  

"(Yosemite) Two other notes:

1) WaveBurner and Soundtrack Pro do not work in Yosemite, when they used to work on Maverick. It appears to me that Apple has really created a difficult permission code for audio on Yosemite.
(He sent a large screenshot of WaveBurner crash report, headline "WaveBurner cannot be opened because of a problem".)

2) Snapz Pro Report: (follow-up to prev. comments on v2.5.4 audio capture problems)
Reply to Ambrosia Software Support request:
"We are aware of the incompatibilities between Snapz Pro and Yosemite and while there is an update planned for the near future we cannot give you an ETA of the release."

---

That's it for now.
-John"

Thanks again.
  

• OS X Mavericks: About Activity Monitor

More at page of Tips, Troubleshooting & How-To articles for Mac/OS X/iOS Users.
  

• Ars has an updated article on Bootcamp/Gaming on the Retina iMac and its 5K display. Includes benchmarks vs 2013 iMac.
• Youtube Video: GeForce GTX 970 in Mac Pro vs. Hackintosh
  (1st test is Mac Pro with ATI 4870 card, GTX970 used in later runs)
• NewerTech Wireless Aluminum Keypad Line Adds Black Key Choice (sponsor blog)

Monday, Oct. 27th News
• Nvidia Driver Update 343.01.01f02 for OS X 10.10.0 (Yosemite)
• About Power Nap (and macs that support it)
  
• Guide to Installing OS X on an external volume
  
• How to Create a bootable installer for OS X Mavericks or Yosemite
• OS X Keychain Access asks for keychain "login" after changing password
• Get help with hardware features on your iPhone, iPad, and iPod touch
• MacBook Pro Frequently asked questions about using a Retina display
• Using Apple Hardware Test (for pre-2013 Intel-based Macs)
• iPhone: Wireless carrier support and features
• iOS: Understanding captive Wi-Fi networks
• Reader Feedback on Mail app in Yosemite
• 2011 iMac owner on high CPU usage in Logic with OS X Yosemite
• Civilization: Beyond Earth Mac and Linux Dev Update 1 (aspyr blog)
• A look at OS X Yosemite and iOS 8.1

For links to older news pages, see the Archives.