Who is affected
The following is confirmed by me [ in Win 7 X64 RC ] and by a colleague of mine who is a MSDN subscriber who has access to the final / RTM Windows 7 X64. It is NOT a Sonar 8.5.1 issue - it is an O/S issue. It is also NOT present in Vista SP1 x64 or X32. It only applies to Windows 7 X64 and X32 and only in systems using more than 2 physicial CPU's and/or more than 2 "logical" cores - ie: Core i7 DAW's.
The Problem
Core Parking is VERY bad for DAW's - great for non-DAW Laptops - but very bad for us in the DAW world.
See here for a bit of info / explanation / more info about CPU Core Parking - http://channel9.msdn.com/forums/Coffeeh … n-4-cores/
Without the following " fix " you will see massive CPU spiking in Sonar and Windows Task Manager - some CPU cores will be "turned off" / "parked" depending on load and they will be dynamically turned on or off and dynamically loaded up or down as the system deems necessary - the scope for glitchs / pops / clicks / droputs etc.... in such an environment is simply enormous.
To the best of my knowledge, there is no known "switch" to turn it off - no utility I am aware of to "tweak" it off.
The Fix
- go to REGEDIT
- Search and Find this key [ 54533251-82be-4824-96c1-47b60b740d00 ] without the " [ ] "
- alternately, you can search and find the phrase " Core Parking " - again without the " "
- either of the above searchs works and delivers the exact same results
- delete the key(s)
- make sure you search the whole Registry - you should find it [ from memory ] 6 times but will only be able to delete [ from memory ] the first 2 or 3 instances - dont worry about the ones you cant delete - just delete all the ones you can
- exit the Registy
- Shutdown Win7
- Do a full cold shutdown and re-boot
The Result
Perfect* load balancing across all you CPU cores - no spiking - both in Windows 7 Task Manager and Sonars CPU meters
Hope the above is of help.
Tom
* - you will still see some " unevenness " depending on the EFX / VST / Synths etc... you use because unlike Sonar - which is excellently "coded" to be multi-thread aware, compliant and cpu-load-balanced, many, many other EFX's / VST's / Synth's etc... [ most actually ] are very lazily and poorly coded / written and are no-where near as " even " when it comes to multi-thread awareness, compliance and cpu-load-balancing.
<message edited by TomG on November 01, 09 5:28 AM>