3000, whaaaaat!?! Generally you want to keep dmap resolution as low as possible. It's a balance between mainly resolution and filter size. The goal of course is to get descent shadows as quickly as possible. I got many lights on my Andrea Gail project. Currently I'm adding lights inside the cockpit. I've found out that a resolution of 64 and filter size of 2 is enough for these lights (frame resolution is 720x432)...