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by josephg 881 days ago
Yep. Adding "-C target-cpu=native" to rustc on my desktop computer consistently gets a ~10-15% performance boost compared to the default target. The default target is extremely conservative. As far as I can tell, it doesn't take advantage of any CPU features added in the last 20 years. (The k8 came out in 2003.)
2 comments

Red Hat Enterprise Linux has upgraded their default target to x86-64-v2 and is considering switching to x86-64-v3 for RHEL 10 (which should release around 2026?). I'd take that as a sign that those might be reasonable choices for newly released software.

Some linux distros also give you the option to either get a version compatible with ancient hardware or the optimized x86-64-v3 version, which seems like a good compromise.

Those Gentoo people were onto something.
Funny that it stopped being the case for a while around 2006. AMD64 became widespread while also being very new, closing the gap between "default" and "native".
Of course, gentoo just started using prebuilt packages a few months ago…