SharePoint 2010 – slow Full Crawl

I’ve been challenged with reducing the amount of time for our Full Crawls.  We are crawling currently about 1.6 million docs. Our crawl rate is terrible.  It’s anywhere from 18 to 21 hours.  The incremental crawls however are MUCH faster.

I have a dedicated crawl server setup  – 6 Procs – 16 GB of ram. Plus I am using the Application server (same specs) as a secondary crawl server.

It’s my understanding we should be hitting a crawl rate of around 45 docs per second. We are not even close to that.

What I’ve tried so far..  creating a new content source – Index Reset – Full Crawl.
Turning off – Offload Task and Chimney on SQL and Crawl servers.  Disabled A\V checks during that time. 

Looking for suggestions….

Thanks SP-C