Some people who have updated their Macs to OS X 10.10.3 are noticing dropouts in Wi-Fi connectivity. While such problems have affected past OS X versions, in these cases often the problems only started after updating to version 10.10.3, and not before. Whenever Wi-Fi problems crop up in OS X, unfortunately there can be a myriad of reasons that might take meticulous troubleshooting to fix; however, one issue that seems common to many affected people is some interference with the iCloud syncing features in Photos.
When you updated your Mac to OS X 10.10.3, you will have installed Apple’s new Photos program that is a replacement to iPhoto and bridges the Photos experience with the Photos experience in iOS. As with the iOS version, this not only manages your photos in a local library, but also syncs them to iCloud, and the way Photos handles them appears to be causing some Wi-Fi connections to be lost.
- Open Photos.
- Go to the Photos > Preferences menu.
- Go to the iCloud section.
- Uncheck iCloud Photo Library
After doing this, see if your Wi-Fi connection becomes more stable. If not, then try unchecking the other options in this preferences setting, including My Photo Stream and iCloud Photo Sharing.