I think DNN does use up more memory than standard sites and it's to be expected based on the nature of the product - i.e. it is an application!

However, I do know that there seems to be a level on which a mix of extra traffic, memory leaks and one too many sites seems to push DNN to it's limits.  I know there is someone having some difficulties with their 7,000 rich child/parent potal setup which is causing some grief at the moment.

I ended up buying my way out of the problem - new server - upgraded from 2.4gb hyperthreaded with 2gb of ram, now on a dual core, dual 3.2 xeon processors, with 8gb of ram.  What was done (please excuse my lack of correct teminology - I had this professionally installed) - was analysis on what was going on the server, and raid 5 configuration, with separate drive for sql and web, and backups - 24gb pagesys file and sql is running now with up to 3gb of ram. 

It's been an interesting transistion - the machine still spikes overall very smooth running and much much faster speeds, and absolutely no performance issues which is great. I think I can put up to 12gb in that server.  My next step is to replicate the server and having it purely serving sql - which at the moment I'm running web/sql - not always the best environment but that's what we live with.

It's interesting reading about these problem, solutions, ideas and all the contributions here certainly help us understand dnn and it's requirements further and I know that the core team is also working on optimisation in areas, its' simply not there at the moment.

I think it also depends on what you're running since at the moment - my sql is running on 1.7gb out of the 3gb without a problem, but I can see over time it's going to need more.

Thanks for your input guys - I'm learning alot from everyone else's experiences.

Nina Meiers