Traffic shaping on debian

Hi guys!

I have a debian box acting as a router and need a tool to perform 
traffic shaping based on source/destination IPs, interfaces, etc. I have 
tried the default tc, however, it uses plenty of resources, e.g. 600 
mbps without shaping flows through with 3% cpu load and the same 600mbps 
with shaping (tc using htb on egress interface) consumes something like 
40% cpu.

Probably someone could advise some kind of a tool to do such shaping 
with minimum resources consumed - I've searched through the web and 
found a module named nf-hishape, however, I didn't manage to find some 
reasonably high number of articles about it as well as no manuals and so 
on - I guess it's not very popular (if it's actually alive).

Any help would be appreciated.

Thanks in advance.