Suricata

When I use the pcre keyword to detect pcap. It alerted 156 times.
alert smb any any -> any any (msg:"smb test";pcre:"/test/";sid:26;)

But, Change pcre keyword to content keyword, it alerted 5 times.
alert smb any any -> any any (msg:"smb test";content:"test";sid:27;)

What caused this?
Does PCRE change the detection mode ?
If this is the reason, What keyword can make pcre keyword like content keyword work?