I have an iMac that's about 4 months old. Recently I've noticed my Internet speed has dropped from around 15mbps download to 4-5mbps. At first I assumed it was my ISP but my iPhone and iPad are both testing at the right speeds which tells me it's my mac. I've done a reboot and have also tried Chrome, Safari, and Firefox and they all come up with the same results. Any tips are greatly appreciated. FYI I'm hooked up with Verizon Fios.