I have 5 large sites and I just put one of them on a new server... I wanted to do some stress-tests and spike the load on the main site on the new server, so I put iframes in the footer of the 4 other sites which point to the main site on the new server. It only adds a few seconds to the page load, and they have no borders, so they are undetectable to the eye. Will google penalize me for doing this? Is there a time-limit that I have to run these tests before it may turn google angry?
No Iframes doesn't penalize you. I came across a site ranking high for a competitive word in google that was using iframes to send you to another page.