I have iMac 27inch 2010 operating on Sierra 10.12.6. It runs slower than previous OS systems, is it OK to upgrade to High Sierra or will it cause me more speed issues or make my computer crash and burn!
macOS Sierra (10.12.6), Memory: 8GB 1333 MHz DDR3
If you want to determine how well High Sierra runs on your present hardware you can follow the procedure in Upgrading macOS without fear. When asked if you want to transfer information from another Mac you can elect to do that at your option, or at some other time using Migration Assistant.
If and when you are satisfied HS runs acceptably well for your needs, you can either upgrade in the usual manner, or restore the contents of that trial installation to your usual startup volume using Disk Utility's Restore function: Restore a disk - Apple Support.
You ought fix operational problems before upgrading. EtreCheck will help with that. Needless to say, if you are using any non-Apple "anti-virus", "cleaning", "cleansing", "washing", "Internet security" junk, anything at all in those broad categories of useless garbage, don't. A lot of things won't work if you do.
If you think there might be a problem with your Sierra install then it is best to sort out what the problem is before upgrading to High Sierra as you may make the situation worse.
Download and then install this, http://etrecheck.com/ run the app and post the results back here.
the app is useful in diagnosing issues with your mac, no personal data is disclosed.
OS System upgrade - Yes or No?
