That's very interesting Simon. Thanks for taking the time to set this up and for your informed insight. Always appreciated.
Jeff
Always a pleasure Jeff, you know I like to nerd out a bit

Thank you, Simon. Fascinating and helpful. I think yours is the first-ever mention of advice where to store the generated tracks for best speed.
My empirical experience, with absolutely no scientific tests, is that starting and using the program feels ‘snappier’ if it’s on an SSD. But generating songs works remarkably the same on my two computers, one of which has the RealTracks on a 10k internal hard drive and the other on the supplied PG Music external drive. On both computers, the program loads from an internal SSD, so the only difference is the location of the RealTracks. Note: audiophile version on both.
Simon, would you consider writing a post for Tips and Tricks? Perhaps something like, What speeds up BIAB, and what doesn’t?
Yeah, I don't think it's been brought up before or at least not in detail, but it makes sense that it would be faster if you're not writing to the same drive while reading from it. Figuring that out was almost accidental while I was doing the above testing

I agree that the program feels a little snappier from an SSD when it's initially loaded (probably the spinup/seek time or lack thereof), but once it's going most of the program is in memory so it shouldn't make much difference in theory. For me the bottleneck is the 10-year-old i5, as otherwise I've got 16gb of ram and two SATA SSD's.
I'll think about a tips'n'tricks - what I already posted before is a good start, but I don't know of much more that can be done.
I have observed the same. By changing the location of the "Saved Tracks" to the ssd (C:\) of the main program, I went from generating 30 seconds to less than 10. Very cool.
That's a much bigger difference than I had! Are your Realtracks on a USB drive or something else?