I did what I always do: spent too much time on eBay, saw six network ports and a $20-ish price tag, and impulse-bought a weird old Riverbed Steelhead CX-570 without even really knowing what it was. It turns out it’s a business “network acceleration” appliance, meant to sit between LAN and WAN and do caching/TCP optimization stuff. I didn’t buy it for any of that, though—I bought it because it looked like it could be a killer budget DIY router if I could get OPNsense running on it. Getting there was the fun part. I had to use the front RJ45 serial console (and figure out it defaulted to a painfully slow 9600 baud), then I swapped the loud stock fans for quieter Arctic 40mm units, replaced old thermal paste, bumped RAM up to 8GB (then 16GB dual-channel), and moved to SATA SSDs. OPNsense installed cleanly via the serial installer, but four of the six NICs were “dead” thanks to a LAN bypass relay setup—until I found the BIOS option to force the relays on at boot. After that, it pushed full gigabit in iperf3 with low CPU usage, and I even dropped idle power to ~22–23W by unplugging the lights-out module. Under the hood it’s an Ivy Bridge embedded Pentium (B925C) with AES-NI, plus a weird backwards PCIe slot that surprised me with PCIe Gen3 x4 support. It’s long, a bit awkward, and stuck at gigabit—but for the money, it’s a surprisingly solid router platform, and there’s honestly not a 0% chance I end up using one in my next network rebuild.