You need to try a better autorouter.

My experience with PADS/Mentor "blaze router" and "Specctra" (now Allegro PCB router) was very good. Altium on the other hand... no (I mention Altium because I think most people's bad experience is coming from this).

Specctra and blaze worked fine in 1998-era PC hardware. I used them for high speed designs (even then we had ECL and PECL).