Note that the hashbrown crate uses FxHash by default, so the second table is the fair comparison. When ported to the stdlib it will likely be changed to have SipHash as the default.
For the standard hashmap, replacing SipHash with FxHash gets you a 4x perf boost. Replacing the standard hashmap with hashbrown gets you a 2x perf boost (when you're using FxHash, there are no numbers here for when you're using SipHash but I suspect it will still be significant, if smaller)
https://github.com/Amanieu/hashbrown#performance
Note that the hashbrown crate uses FxHash by default, so the second table is the fair comparison. When ported to the stdlib it will likely be changed to have SipHash as the default.
For the standard hashmap, replacing SipHash with FxHash gets you a 4x perf boost. Replacing the standard hashmap with hashbrown gets you a 2x perf boost (when you're using FxHash, there are no numbers here for when you're using SipHash but I suspect it will still be significant, if smaller)