Q: My IT department claims it should be a simple matter to upgrade my older iMac to the new Mavericks operating system. I bought the iMac, which has the Snow Leopard operating system (version 10.6.8), in December 2007.
I'm always suspicious when people use the word "simple" in such contexts, but I was really struck by your claim in a recent column that upgrading computers that are five or more years old almost never works well.
Are there problems I should watch out for in updating from Snow Leopard to Mavericks? Would I be better off to buy a new computer rather than upgrade a machine that is more than six years old?
Steve Buechler, Mankato
A: This is how borderline your computer is: If it were only a few months older (from before mid-2007), it wouldn't qualify for the upgrade at all.
The main issues in the upgrade are the operating system your computer is using and the amount of random access memory (RAM) it has. You've already met the first requirement by having the correct version of Snow Leopard installed. But the amount of RAM in your iMac is probably insufficient.
Apple says your iMac needs 2 gigabytes of RAM to run the Mavericks operating system. But some online Apple forums say your iMac needs 4 gigabytes of RAM or it may run slowly.
While any iMac of your vintage can accommodate up to 4 gigabytes of RAM, yours may have been sold with less, perhaps as little as 1 gigabyte. To determine how much RAM your iMac has, go to the Apple menu at the top left of the screen and choose "About This Mac."
A decision to upgrade boils down to getting by now but limiting yourself in the future, because you may not be able to add more software without slowing down the computer.
For a list of other older Macs that can be upgraded to Mavericks, see tinyurl.com/c6wbkks.
Q: I've heard that you should let your laptop computer battery run down to 10 percent before recharging it. Is this necessary? I normally use my laptop while it is plugged in to the power. Am I damaging my PC by doing this?
Lana Luhm, Eau Claire, Wis.
A: Batteries for laptops and other electronic devices do wear out from being charged. So, to minimize the number of times the battery is charged, use it until it is nearly run down.
No, you're not hurting your computer by running it with the power cord plugged in. But there is a theory (no real proof) that batteries that are always plugged in have their lifetimes reduced. The purported reason is that holding a full charge puts more stress on individual battery cells. According to this theory, laptop batteries last the longest when they are charged to only 70 percent of capacity before being used. See tinyurl.com/n2mvenv for a Wired magazine article on this topic.
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