10'000'000 elements

container	insert	find	maxrss
google::sparse_hash_map	6.39060	1.818	173MiB
tsl::sparse_map	3.51809	1.76211	218MiB
sparsepp	6.24339	1.78245	229MiB
folly::F14VectorMap	1.85791	0.79995	264MiB
folly::F14FastMap	2.34196	0.99701	392MiB
robin_hood::unordered_map	1.33476	0.86814	411MiB
phmap::flat_hash_map	1.34150	1.39412	411MiB
folly::F14NodeMap	2.42989	0.79106	441MiB
google::dense_hash_map	1.75558	0.99429	770MiB

1'000'000'000 elements

container	insert	find	maxrss
google::sparse_hash_map	717.639	227.964	17575MiB
tsl::sparse_map	306.876	113.303	20071MiB
sparsepp	390.99	142.251	19807MiB
folly::F14VectorMap	134.315	49.4222	32921MiB
folly::F14FastMap	140.811	61.6684	49304MiB
robin_hood::unordered_map	114.843	55.5778	52227MiB
phmap::flat_hash_map	96.6087	86.0701	52227MiB
folly::F14NodeMap	195.283	49.7657	49288MiB
google::dense_hash_map	89.6095	58.1243	49155MiB

NOTE: This numbers was generated on a different machine then 10'000'000 elements