Sparc is not for performance, particularly for benchmarks. BTW, even Linux lose benchmarks to windows often times.
We used a Sparc Ultra 10 for a Authentication server in 2000, it supports concurrent 100K users without any issue, obviously you need to write your own software, but the server is super stable. And yes, we use cheap x86 + Linux for all sorts of thing from 1996 and it was quite faster but you can not trust it the same way as a Sparc.
For a brief moment before epoll came along it looked like Linux would get /dev/poll.[1] In fact, IIRC, epoll started as a /dev/poll implementation. I don't think Sun's /dev/poll ever saw much uptake because, aside from the limitations mentioned the kqueue paper, the pace of software development was much more rapid and dynamic in the FOSS and web worlds, and the center of gravity had already shifted to BSD and Linux.
For better and worse, Linux developers seemed more inclined toward adopting extensions from SysV and SunOS/Solaris than from the contemporary BSDs.
And then Solaris added EventPorts in reaction to kqueue. Arguably they should have just adopted kqueue. Would be much better if both Solaris and Linux had just adopted kqueue. Having that unified accross the 3 major server OSs would have been helpful.
Been there done that? Circa 2001 I had a customer with a rack of 220R's and Clariion storage arrays. I was paged about an app outage and saw (IIRC) "environmental errors" in the logs about the temperature of the machines. One of the Clariion's, in the same rack, had caught fire which brought the database / app down but the 220R's kept chugging along. Unsurprisingly this was quickly followed a call from the NOC that the fire suppression kicking in and that I should down get there ASAP.
We used a Sparc Ultra 10 for a Authentication server in 2000, it supports concurrent 100K users without any issue, obviously you need to write your own software, but the server is super stable. And yes, we use cheap x86 + Linux for all sorts of thing from 1996 and it was quite faster but you can not trust it the same way as a Sparc.