We are currently testing DNN 4.5.3 on a dual core 4GB server with SQL Server 2005. We are using a customised version of the HTML/Text module and a procured search engine from Xepient. The customizations are relaitvely simple (they add a simple workflow model) and do not require any exceptional resources.

We are using disk based caching and peformance set to light caching mode.

We have noted that the memory usage of the w3wp process associated with the IIS application pool for our site gradually increases. During heavy load the memory usage reached 1.5 GB (the memory assigned for application pool). This is huge given that the the maximum number of users is no more than 10 and that we currently have approximately 300 pages. This was reached in under 24 hours (the process recycling setting)

Has anyone else experienced similar problems? Is there something obvious I am missing?

Using that much memory just for the worker process is not normal, especially if you are using disk based caching for the modules.

You may need to disable or hide some things to determine what is causing the memory usage to grow so large.  It seems that it grows rather quickly, so it might not take long to figure it out. 

I'm not sure why Mitchel said you need more caching. Maybe he can elaborate, but if you switch from light to heavy caching your objects will be cached longer so you can expect the memory  usage to increase.

duplicate post...