Hi everyone.
I’am a desperate user and I ask the community to help me as a last chance !
I recently updated Nuendo 7 to 8…
And I used to update at the same time my yosemite under Sierra in a mac pro 5.1 with 2 cores 3,46 Ghtz (24 Threads) and 128 GB of RAM. 
A raydat from RME with an Aurora.
My sadness is that with 4 audio tracks recording at the same time, the software is totally unusable with Huge Asio issues performances. 
A lot of tests with Asio guard, within it, with hyper threading, without it (using Instruments from Xcode).
And all of this at a buffer size at 128.
Under Yosmite, everything is changing, and working with “normal” performances but with graphic issues…
I’ve read a lot of topics and as a big fan of Steinberg from a lot of years (20 years) for the first time I’am answering myself to leave.
With Ableton the same configuration go with 2% !!!
Please Help !!!