Hashcat running on a Amazon p3.16xlarge (8 Nvidia Tesla V100 GPUs) does 115 BILLION salted SHA-1 hashes per second. Based on that, most weak passwords are cracked in seconds, even if you have per user salts.
>To a modern attack, salts quite simply don’t help.
Everybody should really move to key derivation functions (ideally scrypt)
What parameters do you recommend?
Is N=14, r=8, p=1 good enough?
The usual answer is to choose the parameters in such a way that targets the largest verification time that your servers can stand. I'm not aware of a recommended minimum value. In general, though, you're making a pretty good choice by choosing bcrypt, and so long as you're using the above you should have far better security as compared to sha*/md5/etc