Where best to cache the disk

We are not using raw partitions for our tablespaces. Are we better off caching inside Oracle by using a large SGA and a small Unix disk cache or should we use a small SGA and a large Unix disk cache?

I am tempted to assign all our spare memory to the Unix disk cache (by increasing NBUF etc) and to keep the SGA just big enough for DC_* dictionary caching.

What say you?

-- 
Paul Beardsell                          SAM Business Systems Ltd
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