Dear papi61,
thank you for your response.
Just to make sure: the external USB 3.0 drive just carries the project data. System and Cubase are of course installed on an internal SATA drive. The USB drive works fine otherwise (fast data transfer, I can use the full 4 TB space when formatted with NTFS in GPT mode). Its just that problem with playback in Cubase.
I agree with you that internal drives should show a better performance, nontheless I should stress that I usually have really small projects with less than 10 audiotracks, no instrument plugins and maybe just 2 or 3 simple effects. As I said in my posting, they work fine even on USB 2.0 sticks and also the small 2TB WD HDD did not show any problem.
So I am still not sure a 100% whether the brand (Seagate) is the problem or whether Cubase just works with drives max. 2 TB (once more, I am only talking about the project data, not OS or program code).
Once more thank you for taking your time to respond.
Best Wishes for the New Year.
Cheers
Gerry