I use SampleTank 3 at the moment and have a project in Cakewalk with 14 MIDI tracks. For years I've always opened one instance of ST3 and routed all MIDI tracks to it on different channels. I recently upgraded my PC to an i9 processor, 32GB of memory and 14 threads. Now I get severe crackling using 1024 samples or less, total drop out at 128. My interface is an RME Aio on Pci card.
If I load different instances of ST3 - counter intuitive as it is multi-timbral - I can go down to 256 samples with four instances, and no crackling.
I was wondering if ST4 supports multi-threading in which case I shall probably upgrade.