Now in the era of 8GB RPi, did anyone tried to run it from something like RAM drive? Will this matter for anything, like synths load times, boot time, preset loading, whatever?
My linux knowledge is not enough to try myself, but can anyone experienced make a try?
(preload could be done from some squashed archive to speed up loading time?)
I run my homebrew zynth on a pi 4 with 4gb of ram and it boots from a usb3 ssd drive. It performs well. I’m not sure quite how much better than on SD it is, but it can stream samples quick 
Sure SSD over USB3 can perform better, but I don’t want anything hanging off the device. But I guess if it would be runnig off the RAM, things could be lightning fast.
Yeah, I guess my point is that the SSD shifts data about 20x quicker than the original SD but the gains are maybe not as big as you would expect.
On the other hand though, it’s a lot more stable and rarely, if ever, xruns
Hmm… I guess full system image won’t fit into RAM (my live fs have arount 9GB), but what if just needed parts (zynthian, python, ???) would go to RAM disk, and what if all writes except settings updates would go to RAM (or /dev/null if not necessary)? There is no inherent cache and command queuing in SD card, I can imagine that multiple reads/writes occurs from OS point of view concurrently. Though SD cards sequential reads are perfectly usable, what ruin real performance is those “block seek” times, which are in matters of milliseconds (1-8 in my experience).