feed cat

$ cat= ; i=0; while true; do echo "Feeding $i cats:" ; eval "pv -Ss $((1 << 32)) -r </dev/zero $cat >/dev/null"; cat="$cat |cat"; i=$((i+1)); done
Feeding 0 cats:
[21,4GiB/s]
Feeding 1 cats:
[3,51GiB/s]
Feeding 2 cats:
[3,34GiB/s]
Feeding 3 cats:
[2,88GiB/s]
Feeding 4 cats:
[2,42GiB/s]
Feeding 5 cats:
[2,26GiB/s]
Feeding 6 cats:
[2,12GiB/s]
Feeding 7 cats:
[2,00GiB/s]
Feeding 8 cats:
[1,72GiB/s]
Feeding 9 cats:
[1,53GiB/s]
Feeding 10 cats:
[1,36GiB/s]
Feeding 11 cats:
[1,24GiB/s]
Feeding 12 cats:
[1,14GiB/s]
Feeding 13 cats:
[1,07GiB/s]
Feeding 14 cats:
[ 953MiB/s]
Feeding 15 cats:
[ 937MiB/s]
Feeding 16 cats:
[ 843MiB/s]
Feeding 17 cats:
[ 716MiB/s]
Feeding 18 cats:
[ 693MiB/s]
Feeding 19 cats:
[ 677MiB/s]
Feeding 20 cats:
[ 649MiB/s]
Feeding 21 cats:
[ 618MiB/s]