Hello, We have been apache users for many years. Until now and in previous apache versions , by default, in the Multi-Processing Module the prefork and worker modules were used. Now in the latest versions Event is used. We have been doing tests (with php (wordpress web)) and it seems that the amount of memory occupied by the processes is much higher. We have also verified that having several CPUs the amount of memory occupied by each process is greater than if you have a single CPU. In others servers with apache 2.2.34 (for example) and Prefork module the Average process size (MB) is around 80. Now, with event module is around 250-500 (see below) Do you have information about it? How can I calculate the configuration parameters? This is the default configuration <IfModule mpm_event_module> Start Servers 3 MinSpareThreads 75 Max Spare Threads 250 Threads Per Child 25 MaxRequestWorkers 400 MaxConnectionsPerChild 0 </IfModule> We are monitoring it with this command: ps -ylC httpd | awk '{x += $8;y += 1} END { print "Apache memory usage (MB): "x/1024; print " Average process size (MB): "x/((y-1)*1024); print "Apache Process: "y-1;}' TEST 1: 1CPU & 4GB RAM => Apache memory usage (MB): 1141.29 | Average process size (MB): 228.257 | Apache Process: 5 TEST 2: 2CPU With 1 Socket & 4GB RAM => Apache memory usage (MB): 2882.71 | Average process size (MB): 576.543| Apache Process: 5 TEST 3: 2CPU With 2 Socket & 4GB RAM => Apache memory usage (MB): 2008.18| Average process size (MB): 401.636| Apache Process: 5 Regards, Carlos |