I was always blown away by how much more efficient FreeBSD's network stack was compared to Linux at the time. It convinced me to go FreeBSD-only for a few years.
Do you consider that not to still be the case?
After that, Intel and AMD have introduced cheap multi-threaded and multi-core CPUs. Linux was adapted very quickly to work well on such CPUs, but FreeBSD has struggled for many years until reaching an acceptable performance on multi-threaded or multi-core CPUs, so it became much slower than Linux.
Later, the performance gap between Linux and FreeBSD has diminished continuously, so now there is no longer any large difference between them.
Depending on the hardware and on the application, either Linux or FreeBSD can be faster, but in the majority of the cases the winner is Linux.
Despite that, for certain applications there may be good reasons to choose FreeBSD, even where it happens to be slower than Linux.
I'm not denying this, but do you have a source? I've been trying to find modern "Linux vs FreeBSD" performance tests but haven't been super successful. Mostly I find things from the early 2000s when FreeBSD had a clear lead.
Do you have any data to back that up? Everything I've seen recently and my own experience tells me this isn't the case but I also don't have any data to back up my position. Would love to find some good data on this either way.
In the early years, I have run many benchmarks between them, in order to choose the one that was the best suited for certain applications.
However, during the last decade, I did not bother to compare them any more, because now the main reasons why I choose one or the other do not include the speed.
Even if I have right now, besides me, several computers with FreeBSD and several with Linux, it would not be easy for me to run any benchmark, because they have very different hardware, which would influence the results much more than the OS.
For all the applications where I use FreeBSD (for various networking and storage services), its performance is adequate, and I use it instead of Linux for other reasons, not depending on whether it might be faster or slower.
In the applications where computational performance is important, I use Linux, but that is not due to some benchmark results, but because some commercial software is available only for Linux, e.g. CUDA libraries or FPGA design programs.
Many benchmark results comparing FreeBSD and Linux may be influenced more by the file systems used than by the OS kernel.
I have seen recently some benchmark comparing FreeBSD and Linux for a database application dominated by SSD I/O, but I cannot remember a link to it.
The only file system shared by Linux and FreeBSD is ZFS. With ZFS, the benchmark results were similar for Linux and FreeBSD. However, FreeBSD was faster when using UFS and Linux was much faster, when using either XFS or EXT4 (BTRFS was much slower than ZFS). Such a benchmark was much more influenced by the file system than by the operating system.
In conclusion, it is very hard to make a good comparison between FreeBSD and Linux, because you need identical hardware, which must be restricted to the shorter list that is well supported by FreeBSD, and you need to run some micro-benchmark testing some kernel system calls.
Otherwise, the result may depend more on the supported software, hardware or file systems, than on the OS kernel.
But you're right, in the end you just have to set up both for your particular use case with the best optimizations each has to offer and see which performs better.
At the scale of Google / MS / Amazon / Apple if servers would run faster of BSD* they would use it. We're talking about 10's millions of servers here.
https://www.phoronix.com/review/bsd-linux-eo2021/7
It gives you a pretty clear picture.
There are a lot more factors involved in OS choice that could drive popularity other than the speed of the network stack. And BTW, Hotmail runs on BSD. MacOS is a fork of BSD. And Yahoo ran on BSD (and may still).
Hotmail running BSD is dead, I doubt MS is using BSD at all, they're using the same stuff as outlook.com which is not BSD.
I'm not saying Linux is better, just it is overall faster because an order of magnitude more $$$ and contribution.
I suspect most system administrators and engineers use Linux because that's what everyone else is using.
I remember noticing Yahoo properties being almost unusable in GPRS because they did packet loss detective and recovery in such basic ways e.g. no SACK.