I also absolutely the same !!! Now I work for C8! The C9 is not working smoothly.
Hello Guys.I just downloaded and installed trial Nuendo 7 ,there is different story with Nuendo,much better graphics and usable . Switching back to Cubase 9 feels really bad ! same system ,same computer !!!
I also installed a Nuendo 7 Trials but I have the same problem as C8.5 and C9 in El Capitan! Slow zoom in and out. Graphics problems! 
Apple tends to phase out OpenGL support and use Metal instead to drive the “Desktop Window Manager” of macOS. I personally have found that PreSonus Studio One is the most fluent one under macOS El Capitan and Sierra (more fluent than ProTools). However, its lack of “MIDI sends” made me no choice but keep on using Cubase.
I also met some issue that Cubase crashes on real Mac computers with 16GB-RAM but not on my Skylake Hackintosh w/ 32GB RAM. This also made me wonder whether Cubase could do some optimizations for its memory management.
I also have this problem, and on a brand new iMac specs below:
3.2 GHz Intel Core
32 GB 1867 MHz DDR3
AMD Radeon R9 M380 2048 MB
I’ve been trudging through, since I have no other choice, but it’s adding a lot of stress, not
having things work smoothly like they have for the last 10+yrs I’ve been using Cubase. I hope
the developers can acknowledge this is a valid MAC/Cubase issue, and put resources to fix ASAP.
This is the worst problem I’ve had ever using the software, and I’m torn because I LOVE the new
frequency EQ and other changes they’ve made.
Please fix this soon guys! You’re always ahead of the curve on features, don’t let your MAC userbase
die out due to this bug!
I just downloaded and installed the trial of Nuendo 7, and I am also not experiencing the GUI issues on two projects I tried that do have the issues in C9. It is glorious! 
But this means that the upcoming Nuendo 8 (which is based on Cubase 9) will also have the GUI issue for many Mac users if the issue is not being addressed.
Fabio: This might be very important to note since Nuendo 7 is based on Cubase 8, not Cubase 8.5. We can see here that the issue might seem to have arisen with Cubase 8.5 and higher. Though to further confuse matters, some people are not seeing an improvement with Nuendo 7. So massively frustrating, this situation.
I also download the Nuendo 7 trial and it changed nothing. The playhead still staggers badly when moving the mouse about…normally.
James, are you experiencing the other issues that all of us are experiencing here, or just this playhead issue? I ask because I’ve never experienced it and haven’t seen it mentioned much.
It’s definitely an issue but we need to make sure it’s not a separate thing from what we’re talking about here since your specific issue looks like it’s on Windows as well for some people.
To all testers in this thread:
Please download Quartz Debug and use it by following this instruction:
Then test your Cubase UI responsiveness issue together with Quartz Debug. Any case of having an FPS bottleneck less than 60fps on a 60Hz monitor display mode should be considered as a fluency issue, as currently all Retina Mac models ship with 60Hz display panels. (I personally think that developers should make sure the bottleneck is not lower than 70fps on those 140Hz gaming monitors with high refresh rates.)
Everyone please bear in mind that FPS is not a game-only matter because Apple uses FPS to measure the fluency of UI rendering process.
I just tested Nuendo 7 and I’m NOT getting the GUI issues I’ve had since Cubase 8.5. I have 3 different Macs with the GUI issue regardless of OS(Capitan,Sierra). Nuendo 7 works perfect on all.
Here is something I recently discovered that does not require many tracks but only one to get this sluggish graphics issue.
- Load empty project
- Import a not so short audio file(a few bars)
- Open Quantize Panel and set grid to 1/128
- Set Tuplet to 127
- Now, try to zoom in&out and enjoy the sluggish GUI issue.
Amazing how something as the grid can affect or cause the same issue with only 1 track.
If anyone would like to test this out to see if it’s reproducible, It would kindly appreciate it as it might help Steinberg nail the issue even further.
I tried (with cubase 9.01) what Evertone sugested and I didn’t get any aditional lag (with only one track on an empty project).
I still didn’t download Nuendo 7 demo to see if I still have this lag, however, I downloaded the latest Cubase 8 (8.04 i think) and the lag is still there. (Tested with 8.0, 8.5 and 9.0).
I also tested what ShikiSuen sugested using the Quartz Debug tool from apple and when i’m zooming in and Out with the lag, the frame rate drops to around 2 to 4. When I stop the zoom, the FPS goes up to 30/40.
When I have sometime, I’ll download Nuendo 7 to see if I still have the Lag.
I’m on El Capitan 10.11.6 using GeForce GTX950 with Nvidia Web Drivers
Isn’t it a little supicious that what this guy is talking about:
…is the exact same thing that happens on Windows? If Steinberg can’t even reproduce the supposed Mac-only bug yet, then we don’t know if the problem really is Mac OS’s “OpenGL, etc.”
My issues are specifically poor playhead performance when moving the mouse around in a normal way…especially when hovering over the inspector elements. With little to no CPU stress or HD load.
Please see how poor it is. This is not using a screen capture software as to not affect the video accuracy : https://youtu.be/I3MTvz0JvJw
So I though I should try Nuendo 7 as well. But for my issue…which is a GUI issue as well…there was no improvement.
I guess you won’t meet these issues if using Cubase 6 or 6.5 with latest CoreAudio2Asio patch. (The patch is required, or your class-compliant audio interface may blow your eardrums.)
Yes this created the lag for me
This created the lag for me, as well.
confirmed - also noted my CPU usage when doing this test is about 120 % - when tuplets are reset to OFF is drops to 40 - that’s triple the CPU usage just showing some extra lines on the GUI.
There’s been something off with El Cap and Cubase + Wavelab all the time - where just editing a single wave file will result in a very high CPU / graphics usage so it sets my fans spinning like nuts. This is just from moving the mouse around.
Here’s a video to document and help the developers: http://tonekontrol.dk/temp/IMG_3092.MOV
I can reproduce the lag
I just migrated my Windows 10 Cubase system to a Mac mini and found I have dropout issues as well…
The tracks were directly copied from the Windows system where no dropouts were occurring (actually they were previously but a new nvidia driver fixed that one).
I tried changing the VST priority, disk advanced read time, making sure nothing else is interfering with Cubase process, etc.
I ran the Activity Monitor while playing the track and did noticed it jump to over 100% for a split second.
Specs:
Apple Mac Mini - 3.0GHz Dual-Core Intel Core i7, 16GB Memory, 1TB Fusion Drive, Intel Iris Graphics, Thunderbolt 2, HDMI port, Wi-Fi, Bluetooth 4.0.
I will send Fabio my info as soon as I can…
Hey folks,
Sorry for chiming in as a Logic Pro X user, but I might have some useful information for you here.
Since the latest MacOS and LPX updates more and more Logic users experience issues regarding the DAW’s performance - and just like with Cubase 9 these issues seem to be related to graphics. For example: In my case I am getting bad CPU spikes and audio dropouts when enabling input monitoring on an audio track and playing guitar through an amp simulation on that channel. The dropouts and glitches occur every time there is even the slightest movement in the arrange window (like vertical or horizontal scrolling). Even a simple mouse click in the arrange area will trigger CPU spikes, resulting in audio glitches. If you want further information about it, take a look at a short video clip I posted on youtube to demonstrate the issue and read through the thread on Gearslutz:
The gathered information and the fact that Cubase users are experiencing the same or similar issues have led to the suspicion that the problem might not be rooted in Cubase or Logic but in MacOS itself. It is suspected that Sierra has aggravated some interaction between screen repaints and the audio subsystem - resulting in the aforementioned problems.
So far two ways have been found to reduce (but not completely resolve) the problems:
- Change the Mac’s color profile from the default one to sRGB (sounds weird, but it definitely improves the GUI’s performance, resulting in less audio dropouts and a smoother behavior of the GUI)
- Start the DAW in low resolution mode (right click on the DAW app in Finder > get information > check “start in low resolution”
Also users with Retina screens and integrated GPU (Intel Iris) seem to be affected more severely than others.
Hope I could contribute something useful.