Welcome to the club. There are plenty of threads in these forums on fanless but powerful hardware for OPNsense in these forums. If you're looking for new hardware why don't you do a search for "qotom" and that should give you a starting point for a suitable replacement for your current setup. Unfortunately I can't help too much with hardware as my setup is a VM in a vSphere environment.
If you're looking for something that's relatively cheap ( ~ $150 on ebay), upgradable, can handle 1GbE (it has a 3.1GHz CPU) and low power (idles at 10 watts), then check out the HP 290. There's a big thread below on the many use cases. Unfortunately it's not rack mountable but it is a small form factor. It has one 80mm fan but very quiet.https://forums.serverbuilds.net/t/official-hp-290-p0043w-owners-thread/2829
I very much like my ThinkCentre m720 Tiny. Has a CPU fan but is pretty quiet overall. I’ve got the Intel 4 port NIC installed
I picked up two Dell VFP1445 for $125/ea as new open box on eBay this week. This is my holy grail. I didn't even know it existed until last week. Just keep your eyes posted and you can find some amazing gems.Specs here: https://i.dell.com/sites/csdocuments/Product_Docs/en/vep-1405-spec-sheet.pdfVEP1445C3758 Processor (8 core w/ QAT)M.2 240 SSD with 16G eMMC Flash for recovery OS16G DDR4 ECC(6 x 1G) + (2x 10G SFP+)2 Fans8"x 8"x 2"It has WiFi, but I won't be using it. 802.11ac, 2x2 MIMO, max. phy rate: 866.7 Mbps w/ BluetoothManagement is via serial port only, there is no video out.
Quote from: Greelan on March 23, 2021, 12:10:01 pmI very much like my ThinkCentre m720 Tiny. Has a CPU fan but is pretty quiet overall. I’ve got the Intel 4 port NIC installedYou are probably on the East of the Atlantic, because back here I have searched high and low but not found a Lenovo tiny which could accomodate a NIC card. (ebay and new)