Just wanted to chime in and say the ostinato is Sayuri's Theme from Memoirs of a Geisha. I'm kind of surprised no one answered it yet!Another quick test. Same settings as above, except with 850 instances of Absynth playing 16th notes. (bonus points if you know what score that little ostinato is from)
While there may appear to be a decent amount of CPU headroom left over, Cubase started getting angry when I got over 900 tracks, causing lots of stop and go hitches, even when idling.