It’s probably hard to find smaller ssd’s with any degree of reliability to trust that are used and cheap.
New ones might be an option…just hunt around in the sales or use the one you have.
Awesome thanks. My challenge at the moment is all 8 drives are full (ish) so I’m into the pcie slots so it’s about a £400 investment (card and drive) to “test it” in Africa.
But that does sound promising and still cheaper than a nucleus plus 
It’s all running day in day out with core on my IMac upstairs so yes it seems it was the lack of SSD in the QNAP.
Thanks!!
Yes that is the first problem you run into with a NAS… running out of space! I’ve upgraded my ram from 12 to 24gb and noticed Roon is a lot snappier. The Roon database is now almost 20gb and I can see the core running takes up 2gb of the ram.
I’ve also ordered an i7 cpu so will swap that out to see if there is any improvement. Don’t think there will be much as up sampling the cpu only goes to 10%. Also ordered the nvme card, just waiting on the SSDs to come and I’ll put that in. Then remove the 1Tb SSD I put in one of the drive bays leaving it free for a future HDD.