Not at all, I hashed a 4 character password: h_E@
I then bruteforced it with my GPU using these characters:
Starting from [ ] (4 spaces)
Hash type: MD5, Hash: b77ef9eb5ced73987987fb8846775f24
Device #0: [GeForce 9600 GT] 1500.00 Mhz 48 SP
Found password: [h_E@], HEX: 68 5f 45 40
Processed 92 274 688 passwords in 1s.
Thus, 173 775 306 password(s) per second in average.
I know IPB uses salts but if you have access to the hash then you'll almost always know the salt too.