I often work on several computers. On each computer I would have multiple firefox windows open. Sometimes each computer would have anywhere from 5-10 different firefox windows open at the same time. Then each of these windows would have multiple tabs open. At times each of the open windows could have anywhere from 15 or more individual tabs open. So in total there could be about 150 + different tabs open all at the same time. (eg) WINDOW 1 Tab 1 Tab 2 Tab 3 ---> Until Tab 15 WINDOW 2 Tab 1 Tab 2 Tab 3 ---> Until Tab 15 The same would be for WINDOW 3, 4, 5, 6 --> 10 etc Have have just started using the sync function. But when I go on the other synced computers, under the "History" tab it shows "Tabs from Different Devices". When I open this it does not show ALL of the open tabs from the other computer that it is synced with. Please help . . . Is there a limit as to how many open tabs can be synced?? If so what is this?? How does it determine which tabs will be synced and which ones will not be? Also I have chosen to sync the browsing history. Where is the browsing history synced? Is it merged somewhere or are there still individual records kept somewhere?? Also does the sync function slow down the computer??