proforg@toad-pc:~$ seq 100000000 > 100bln.txt
proforg@toad-pc:~$ time cat 100bln.txt |awk '/200000/ {f=1} {if(f==1) {print}} /800000/{f=0}' >/dev/null

real	0m39.400s
user	0m39.022s
sys	0m6.534s

proforg@toad-pc:~$ time cat 100bln.txt |perl -ne 'print if(/200000/ .. /800000/)' >/dev/null

real	0m43.620s
user	0m43.271s
sys	0m3.742s