I am running a number of SS instances on a DreamHost PS without seemingly a hitch... However, I'm seeing very large RAM utilization compared to other CMS platforms at the moment. This is actually causing something very serious to happen that halts the entire server by running it out of memory and I'm actually very generous in my memory allowances and hosting.

It appears that it is one particular instance of SS that is allowing a lot of stuck scripts to spin on forever. I need to research this quite a bit more and get to the bottom of what is going on.

Any suggestions as to how to isolate this issue out? FastCGI just keeps spawning other procs to handle the load while these others just stagnate.

Have you got any custom code that could be causing any issues? Any large queries / file read/write versions? You should be able to run SS without any issues on DreamHost. (I had the non PS version for a couple years and sure it wasn't going to set any speed records but it was able to handle all the sites I threw at it).

You might want to make sure you are writing to a temp folder by manually creating a silverstripe-cache/ folder in your ss directory and giving apache read/write access and making sure that the manifest is being generated (and therefore cached rather then relooked up every time).