The 3750 does hardware ACL processing in the TCAM. There is no max number of ACL string, it's all a mater of size after it's compile and put in hardware. If an ACL doesnt fit after the merge algo, you will have a message in the log and the ACL will be process by the CPU(this is bad) There is about 1K of space in the TCAM on a 3750 for security ACL and 1K for VLAN ACL if I remember correctly,