Probably, though different. I've had pair.com adjust the max number of httpd's Apache will try to create and that has meant that the web servers aren't having to be rebooted much.

But each web server varies between being unusually fast to respond to being extremely slow to respond.

We have lots of data but I haven't found enough time digging through it to narrow down the cause. Though the performance of the two servers is rarely correlated so the problem probably isn't database-related.