Recommended cache_dir config for large system

[Rhino <rhino@xxxxxxxxxxxx>]

Have Squid2.7STABLE1 running on Debian Linux box with 4 278 GB drives 
allotted for caching.
System has 32 gig RAM, and serves approx. 10k users.
Seeking input as to the most effective config options on this system in 
order to reduce latency
and maximize throughput.
cheers
-Ryan