I have a Mac Pro 2.93Mhz Quad core 10.6.8 and running LR 4.1. How much RAM would you install for good performance; overall, including gradient and brush tool etc. It can take up to 16 gigs.
I would go for 16 GB although Lightroom seems perfectly happy with less (8 or 12). RAM is not that expensive, have a look at OWC website
. Other vendors offer similar prices.
Edit: typo correction