I spent days trying to speed up my slow internet speed on my iMac. My ipad and iphone speed was great. Did a speed test on the ipad, and noticed when I turned off my iMac, the speed shot up.
I happened to turn off Photo Stream, then instantly my iMac speed went way up, and has been perfect since.
This may save someone days of screaming at the iMac.Try it anyway, it certainly worked for me.
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