Speed of -a 7 mode very low !!

[Chick3nman]

No, there is not. This is an architectural problem and not something that can be easily solved. The problem is that the amount of divisible work is different and you cant create enough work for full speed. This wont be possible to fix in this case but it's very similar to the other "more work" scenarios so please read: https://hashcat.net/wiki/doku.php?id=fre...full_speed