I've just been experimenting with the RAM Cache manager, and FWIW I thought I'd share my findings: I ran some simple tests using ab against a single, dynamic page which has some display logic both in the filesystem product and dtml. I cached the index_html using the default RAM Cache Manager settings. Without caching, response time appeared to increase in direct proportion to the number of simultaneous requests up to 10. Above 10 connections, response time worsened dramatically. When there were 15 simultaneous connections, the response time averaged at approximately 10 seconds. The relationship looked logarithmic, but I didn't really take enough samples to be sure. Plus, the system I tested it on only has 96Mb RAM, and it was swapping a bit. In all cases the cache improved performance. The average response time was improved by up to 70% where more than 10 concurrent users were simulated. There was an improvement of 20% - 25% between 5 and 10 concurrent requests. There was no significant improvement where there were no concurrent requests. The relationship between the number of simultaneous requests and the response time remained linear across all measured levels of concurrency. Not exactly a real-life usage scenario, but it sounds impressive :) Not sure I understand what the cache keys are for though... is there any more documentation forthcoming on this?