Hi

I have looked into this and had consulted with the team that developed the Sync service and the thinking is that this issue may not be caused by Sync.

I would recommend clearing the Firefox for Android application cache (not data!), possibly closing one or two tabs and see if you have any applications open on the device that you do not need.

I too have an older mobile device so I am used to a few general performance issues but nothing specific to Firefox (and I use a pre-Release version and am a Sync user).

Thank you,

I may have been too presumptive in identifying the problem. The old Nexus 7 is plagued by storage problem caused by a bad chip, which I assume made the storage performance decay much worse than the other smartphone.

The sync might not be the only one cause of the problem, but I am sure it is one of the triggers for the problem. It may be caused by opening too many tabs, for example, but those can be fixed.

I cannot provide clear proof, but I can say that each time the tablet slows down, as I checked the sync setting it displayed that syncing is in progress or just finished. And if I use other browsers with basic features and lighter than Firefox, there is no slowdown problem. Therefore I feel that the sync interval and only manual sync option is a must for older devices.