Oh wait, I don't think that time is apples to apples:

[ryantm@replit1:~/p/nixpkgs]$ /run/current-system/sw/bin/time nix-build --check pkgs/top-level/release.nix -A manual.inputDerivation
trace: warning: lib.zipWithNames is a deprecated alias of lib.zipAttrsWithNames.
this derivation will be built:
  /nix/store/j622rlm0k013mmspbzgkqgd4zl12vvvd-nixpkgs-manual.drv
error: some outputs of '/nix/store/j622rlm0k013mmspbzgkqgd4zl12vvvd-nixpkgs-manual.drv' are not valid, so checking is not possible
Command exited with non-zero status 1
0.59user 0.18system 0:01.53elapsed 50%CPU (0avgtext+0avgdata 174980maxresident)k
0inputs+0outputs (0major+39908minor)pagefaults 0swaps

[ryantm@replit1:~/p/nixpkgs]$ nix path-info --recursive --closure-size --human-readable ./result
/nix/store/m94bxwbilm1hh0dzk53qs7zvdr1vwsps-nixpkgs-manual     2.0M