Stratus VOS ran on a bunch of non-x86 hardware, i860, PA-RISC, 68000. It wasn't Windows (UNIX admin with a modicum of Stratus VOS experience in production, back in the day).
It seems I encountered the “ftServer” line, which on closer inspection launched in 2001, and was indeed intel/windows 2k, based around Pentium III Xeon Chips.
They still list old product sheets here, the oldest being the ftServer 5200 AFAICT - https://www.stratus.com/solutions/previous-generation-produc...
https://www.stratus.com/assets/5200hw.pdf