Hi,
I was jsut editing an audio project whith a lot of SpectraLayers edits in it.
At one point Cubase warned me that the 2GB file size will be reached when I save the project now. I chose to save anyway because I don’t need the backwards compatibility there.
But after I saved the project since then the saving always takes like around 8 seconds everytime, which is really holding back my workflow. Just before that warning saving was as quick as with a new project.
Any suggestions what to do? 
Only eight seconds for a file exceeding 2GB? You gotta a nice system. I could go and have a coffee.
My thought would be to render those SpectraLayers edits (either through “make extension permanent” or bouncing the clips with the edits). If you need to have the possibility of revisiting those edits later, save the CPR file with the live edits in them under a different name before rendering the edits, thus allowing you to go back and import the needed tracks later if absolutely necessary.
I know different people have different workflow needs on this sort of thing, but I’ve pretty much always used ARA extensions in ways similar to destructive editing, albeit backing up earlier versions of the project files at lots of milestones along the way in case of any need to revisit those destructive edit decisions. In my case, I am primarily using ARA extensions for vocal tuning and tightening background vocals against a lead, most typically with Melodyne and VocAlign, respectively. But when using RePitch for tuning at one point, with the option to store the edits in the project file instead of on disk, I was seeing the same sorts of interruptions to workflow (albeit way before anything close to even 1 GB or 8 seconds – I think I was using a hard disk at that point, too, but even a couple of second or two of interruption every time Cubase saved an automatic backup was disconcerting), and I ended up reverting to the option to save the edits on disk, despite the negatives of that (namely that RePitch wasn’t cleaning up after itself, so those temporary disk files just accumulated until I ultimately cleaned them up manually).
Ok now after closing and reopening the Project it is down to around 2-3 seconds. Probably because now all the history of SpectraLayers is gone and doesn’t need to be saved everytime. Still strange why it was only after reaching 2GB and nothing was slow before that. 