I ran rankmirrors (from pacman-contrib) on the mirror and the 5 upstream i got on https://cloudflaremirrors.com/archlinux

rankmirrors test the time to download core.db from each mirror. Basically this:

  curl -s -m 1 -w "%{time_total} %{http_code}" -o/dev/null https://cloudflaremirrors.com/archlinux/core/os/x86_64/core.db.tar.gz

The results vary a lot sometimes cloudflare mirrors is the fastest, sometimes it's the slowest. Getting anything between 0.07 and 0.30

  $ rankmirrors -t ./ml
  Querying servers. This may take some time...
     *   *   *   *   *   *
   Servers sorted by time (seconds):
  https://ftp.lysator.liu.se/pub/archlinux/$repo/os/$arch : 0.113249
  https://ftp.acc.umu.se/mirror/archlinux/$repo/os/$arch : 0.120371
  https://mirror.osbeck.com/archlinux/$repo/os/$arch : 0.127601
  https://archlinux.dynamict.se/$repo/os/$arch : 0.180493
  https://ftp.myrveln.se/pub/linux/archlinux/$repo/os/$arch : 0.248406
  https://cloudflaremirrors.com/archlinux/$repo/os/$arch : 0.302824
  
  $ rankmirrors -t ./ml
  Querying servers. This may take some time...
     *   *   *   *   *   *
   Servers sorted by time (seconds):
  https://cloudflaremirrors.com/archlinux/$repo/os/$arch : 0.070069
  https://mirror.osbeck.com/archlinux/$repo/os/$arch : 0.081506
  https://ftp.lysator.liu.se/pub/archlinux/$repo/os/$arch : 0.098763
  https://archlinux.dynamict.se/$repo/os/$arch : 0.125846
  https://ftp.acc.umu.se/mirror/archlinux/$repo/os/$arch : 0.127948
  https://ftp.myrveln.se/pub/linux/archlinux/$repo/os/$arch : 0.136529