what’s your current RPi4 setup look like? 4GB or 8GB model by chance? Both USB3 ports used? if not then I’d just grab another external hard drive and use the same RPi for the next node.
I know when I was running nodes on RPi’s, I typically used one per node, but that was usually because I was usb-booting from an SSD, so both USB3 ports used with the SSD and HDD…
If you’re comfortable enough with other linux distros, like ubuntu, there are a lot of alternatives out there. A couple of years ago, I ended up migrating four of my nodes to an Odroid H2+. It has a 4x PCIe 2.0 nvme slot, so I use a WD blue nvme SSD as the boot drive, I shucked two node HDDs from the external enclosures (WD Elements) and connected to the H2+ via the onboard SATA 3.0 connections, and then used the two USB3 ports to connect two more WD Elements external drives. Hardkernel makes/made a nice acrylic case that holds the two bare metal HDDs and computer. So four nodes on one box.
The H2+, which was obsoleted over COVID, runs on an Intel J4115 (quad core) so it’s an x86 processor, and has two SODIMM slots, which I loaded with 2x 8GB RAM. Plus it has 2x 2.5gbps ethernet ports. So quite a bit more powerful than a raspberry pi…
Here’s a picture of that setup in my rack.
It works really well, albeit a bit over kill just for nodes. But it runs rock solid.
Long story short, you could look at some of the Odroid single board computers. They have some really “lite” ones that could run “server” based OS options, and then some beefed up ones like the “H” line up, which they just came out with an upgraded H3/H3+ line up, that can run full windows. Also, not to be confused with the “HC” lineup.
Although, I’d be remiss if I didn’t also point you to this recent thread where Storj specifically states that it would/could be in the best interest of SNOs to not purchase new hardware JUST for storj nodes. SNO's please don't buy anything
Although, they’re really just pointing out the risks when it comes to ROI expectations. To be honest, over the years when I was using RPis…I probably purchased 7 or 8 of them…some used for Storj at one point, and now none of them being used for Storj. Actually most are sitting around collecting dust. I’m perfectly fine with that. Actually, I just purchased some PiKVM boards from geekworm and am using a couple of these RPi4s to run those in servers.