RAM Memory. IOS devices are pretty skimpy. It unloads the website to make space for whatever new task you are asking.
Probably to give you the most current version. What if it's a news site and there was a new story put on and if it didn't refresh, you wouldn't see it. I like that it refreshes automatically.
It is. I've published several benchmarks here in the iOS7 forums. In a nutshell: a medium-sized Web page can easily make Retina iPads allocate 150-200 Mbytes of RAM just for those Web pages. If you open other pages in another tab and the amount of free RAM drops under 100Mbytes, Safari will always free up the for other tabs allocated memory.
Maybe iOS 8 will give some major improvements with RAM management and some tricks with memory compressions like they did with mavericks
I remember my old iPod touch back in 2008/9 would refresh pages.
It's always been the apple way and I've never understood it. Either Apple needs to implement much more RAM or much faster flash storage so that pages can be saved to the storage and recovered from the memory much more quickly!
In practice this means that every time the system needs more space in memory than it currently has available, it "asks" Safari to make some free space. So Safari has to make room by deleting the oldest (by last use) Tab. That's why it can happen, that Safari needs to refresh a page when clicking on its tab. In my experience you can switch between enough tabs to make a normal web-research. But if you multitask and use another app in the meantime it can happen, that safari needed to close a few pages to make sure the other app can work flawlessly.
1. Nope, you don't need another app (user-started process) for background tabs to be unloaded. It'll also happen if you reboot your device (this makes sure nothing runs in the background) and don't start anything but Safari.
2, it's Safari's (more precisely, UIWebView's) enormous memory needs (easily 100-200 Mbytes for a middle-sized Web page on a Retina iPad; on iPhones or non-Retina iPads, the memory usage is much lower because of the lower-res screen) that cause all this to happen. This is why background tabs can instantly be killed if you start loading a large page in another tab - for example, with nin.com.
Don't want to nitpick here, but actually your second point is not the reason for it to happen, but a reason for it to happen that frequently. It wouldn't happen on a PC, because it would use the backing store on the Hard Disk to save unused data, something iOS doesn't.
Nevertheless, Apple could have done better. Just look at Opera Mini. While it doesn't really support scripting / AJAX / dynamic content, it has orders of magnitude less memory requirements (if its proxy server works, that is.) This alone makes it possible for it to load even dozens of nin.com instances without any kind of tab unloads / crashes.
That is, Apple could have produced a little less RAM-hungry engine.
Tap the reload icon. Done.Mine don't ...they never reload .. Only if they are kept in the background for too long... But they should reload! I mean if they don't you can't know if anything has been updated for eg. Comments... So it's proper only .. Nothing dude to "lack of ram"
Tap the reload icon. Done.
I see what you mean now. To be fair they don't usually reload on their own to check for new data (unless perhaps a site specifies that), most of the time when they do it is in fact because the memory they were using before got allocated to something else at some point and when you are getting back to the tab it needs to reload as its previous state isn't saved in memory anymore, so there's a role that RAM can play in that.Sorry I was slow in editing my comment check it again
I see what you mean now. To be fair they don't usually reload on their own to check for new data (unless perhaps a site specifies that), most of the time when they do it is in fact because the memory they were using before got allocated to something else at some point and when you are getting back to the tab it needs to reload as its previous state isn't saved in memory anymore, so there's a role that RAM can play in that.
There isn't a particular count that would do it as it depends on what else might be on your phone how long something has been in the background etc. Some of the other posters in this thread have more technical explanations. Perhaps if you really want to try it out is you can open a number of tabs and then open and run some fairly big and intensive app like a graphics heavy game that you would load and play for a a bit. Then after that try to go back to Safari and see what happens when you go to different tabs.Okay... I tried a little experiment... First opened 3 tabs on safari and switched to each of them
.. And then I opened another app and safari running in the background.. Then I switched back to safari and went on the 3 tabs one by one... Then in the similar way I opened 4 more apps and kept the others running in the back ground, going into safari (and checking each tab)alternative after opening a new app ...
My observation.. None of the tab reloaded.. I know how a tab reloads(with the blue line).. So when according to you should the tab reload..
(I know this was a little desperate)