Wordpress excessive memory usage

My wordpress installation started having internal several errors. I found that about 3/13 memory usage went from 100mb to 400mb, hitting my PS memory limit.

I don’t recall doing anything new about that time. I went and disabled all plugins and memory usage reduced about 50mb. I’m not sure where I should start troubleshooting memory usage issues.

Add your plugins back one at a time…

Very interesting. The same thing happened to me on April 13.

On April 12 I served 20,000 pages and used 64 mb of memory (where it had been for weeks) on my VPS. Then on April 13 I served only 15,000 pages, but memory shot up to 142 mb daily average (where it remains), peaking near 300 mb.

I have a WordPress memory plug-in that tells me that the memory used to generate the pages hasn’t changed.

What I observe is that I have sometimes 10 PHP5 processes in memory with NONE of them actually running.