I am on deadline right now.. don't have a ton of time but wanted to give you something...
I follow almost everything in this guide:
http://www.overclock.net/t/1433882/gaming-and-mouse-response-bios-optimization-guide-for-modern-pc-hardware
this is my shortcut target for Cubase.. I launch from the desktop even though I have Cubase pinned on the taskbar... it just doesn't hold the target settings for me if I don't start from the desktop shortcut EVERY time... so when I go to MIX, I let cubase have EVERYTHING it wants... only during the arrangement MIDI phase will I limit cubase to two cores... then let vienna fight over the rest. My next move is to build an absolute MONSTER dual xeon 44 core (88 with HT) because I have a feeling vienna will know EXACTLY how to use the cores... and basically work with the cores more exclusively... but for now:
C:\Windows\System32\cmd.exe /c start "Process Monitor" /affinity 3F "C:\Program Files\Steinberg\Cubase 9\Cubase9.exe"
On Cubase-> Devices -> VST Audio System...
Release Driver when Application in Background: NOT CHECKED
Activate Multi Processing: CHECKED
Activate ASIO-Guard: ABSOLUTELY NOT! even in VSTi plugin setup in cubase, I have specifically disabled asio guard for vienna plugins. There was a history where ASIO guard + the Vienna BUFFER would FREEZE and do weird things. I don't trust it and my workflow truly doesn't benefit from it... if I DID need it, I certainly would just build two main templates, one for arrangement, and one for mixing with heavy plugs... but I wouldn't be crazy enough to try using MIDI, vienna AND ASIO-Guard.. I mean, I'm not suicidal.
Audio Priority: BOOST
Activate Steinberg Audio Power Scheme: NOT CHECKED (But only becasue I have manually unparked all cores using special registry hacks... there are apps that can do this easily... it wasn't easy to optimize, and I am not balsy enough to try this checked option anymore because it literally messes with your CPU and Power settings every time you check it. I'm worried its gonna screw with my nice low latency setup)
Disk Preload: 2
Adjust for Record latency: CHECKED
ALSO----- i have ASIO latency compensation on BOTH Vienna and Cubase OFF until I'm in the mix stage... the idea being.. I don't want either program introducing artificial delay while I'm mocking up and really want to feel no latency with the performances of each instrument... however once programming is past midi... it might be appropriate to enable those settings for the render in place I just haven't tested enough.. And honestly theres so many variables on the sample libraries, instruments etc... on how much delay exists IN the sample itself to make it almost a non issue in almost every case... I just bounce the loops and then deal with any audio sync problems as needed... maybe nudging stuff forward an back as a whole as a final step...
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Also its important to note I use an app called: Vista Multimedia Scheduler Configuiration Tool
Network throttling index: Disabled
System Responsiveness reserved CPU: 10%
Task: Pro Audio
Affinity: ALL
Clock Rate 10000
GPU Priority: 8
Priority: 1
Scheduling category: High
I/O Priority: Normal
Background Only: False
Background priority: blank
Make sure to backup entries before you jack with this... and SAVE AND EXIT.
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Another important setting for this setup, is the Windows System Properties / (tab) Advanced / (section) Performance - Settings... / (tab) Advaced
Processor scheduling: PROGRAMS
Virtual Memory: 0mb (disabled)
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I use all SSDs: 6 Sandisk 960gb ultra II for normal crap, two samsung evo 850 for operating and daw recording and a Samsung 950 evo for my highest demand kontakt and vsti. I have one older spinning drive for temporary storage which is a SATA internal 3tb drive... this is a staging area to do heavy audio processing, archiving, extraction.. anything that is just wasted write cycles on the SSDs I can do on the staging drive...
NO usb or firewire drives!
NO network shares
NO running processes etc... be smart... fixed IP addresses for all machines... enable net bios over TCP/IP etc...
NO HOMEGROUP CRAP
NO HPET (disabled using "bcdedit /deletevalue useplatformclock" and also disabled in BIOS")
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I see where you are going with the core issue... the best I can do for now is advise setting Vienna options-(tab)-Instances: "Multiprocessing" setting to 2 threads across your entire setup. don't set it to 8.. and DO NOT TRY TO MESS WITH AFFINITY FOR VIENNA... I've tried it... and it actually creates SERIOUS problems for vienna... so leave it be.
by setting it to 2 threads... you are basically using ONE true core (there are really only FOUR cores... the other four are hyperthread virtual cores... BUT for sure, kontakt and vienna LOVE hyperthreading... there is signifigant performance gain of realtime processor calls between NO HT and YES HT... so leave it on.
Then go ahead and just let kontakt have multiprocessor support in its own settings like I said before.... I also do that with Battery 3 / 4 and reaktor.
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overall my RME Raydat is set to 128 buffer... for normal session... 256... in mix stage.. probably getting to 512 and if I bring up Acustica Nebula (for the absolute secret sauce when only the best sounds will do, then I'll take it 1024-2048... with a similar Nebula SERVER setup to the vienna setup...
Remember to just do a system image before you start jacking with settings like this... its so easy to mirror up a drive image (I'm LOVING LOVING LOVING EaseUS Backup software for mission critical imaging and low-profile installs across my machines) Once I've achieved a working setup.. I date and image all machines... because... oh my goodness if one day I wakeup and this thing just doesn't work right... it WILL be faster to flash back to an image than tracking down a million or so potential problems.
WHICH REMINDS ME. WINDOWS UPDATE NEEDS TO DIE DIE DIE DIE... no updates.. or you will have problems.
GOOD LUCK !!!! Let me know how this goes.