JASON SNELL, SIX COLORS:
"The first day I used Photos, I imported a substantial portion of my family photo collection—20,000 or so photos—into what Photos calls the System Photo Library. And set it to upload to iCloud.
"The next day, my Internet connection seemed to die, or at least become sporadically inert. Traffic would sometimes squirt through, but after long delays. It was weird, and intermittent, and I was really sad.
"Later that day I discovered something, though: Even though Photos wasn’t open, a background task was uploading my photo library to iCloud. All 20,000 photos. The process was using all the available bandwidth, saturating my outbound Internet connection and making it essentially unusable."
To find out Jason Snell's solution, click here.