Hey there. I'm running a 13" 2011 MBP. I'm noticing a quiet whir, which I thought was the fan. However, the fan is running at only 2000RPM. My 2009 MBP 13" made no noise at all when the fan was that low. If I raise the RPM just slightly, I can distinctly hear the fan as separate from this other whir. There is no disc in the drive. Am I hearing the hard drive spin? Is there another small fan in the 13" I wasn't aware of? Should the HD be making that faint whir when my previous model MacBook didn't? Are their others out there experiencing the same thing? Thanks.