Memory Hogs

Some programs just don’t politely leave when asked to

A bit of a hog, as well as an elephant
I’ve got myself into a large photographic project that involves scanning loads of old negatives at high resolution, turning them into positive images, and then cleaning them up (in Photoshop Elements). This is the sort of job that requires as much memory as possible, so I’ve been careful to close other programs that I’m not using before I start a session.

The other day I thought I’d have a look at whether anything was running that I’d forgotten about, so had a look in Windows Task Manager. I thought I was going mad when I saw that both Microsoft Outlook and Evernote were using loads of memory even though I was sure I had closed them. So, I opened them again and closed them again. Sure enough, they were definitely using memory, even though closed.

Outlook can use memory even when it is closed
A quick google proved that this is a real fact, and it turns out that there is a simple solution. Instead of closing the program the quickest way – by clicking on the “X” in the top right hand corner of the program’s window – go instead to the “File” menu (if there is one) and close the program with the “Exit” option (usually found at or near the bottom of that File menu).

I haven’t investigated the whys and wherefores of this phenomenon, but it’s a little trick you might find useful if your computer is a bit challenged memory-wise, or if you’re doing something that can usefully use all the memory it can get access to. My computer has 16gb memory. Normally that is plenty, but scanning negatives at 2400dpi pushes it hard (each scan starts off at almost 250mb).

If you want to see what’s using all your memory, one of the easiest ways to open Task Manager (in Windows only, of course) is to  give the old three fingered salute (Control, Alt, and Delete) and then click on Task Manager in the menu that pops up. Alternatively, just type “Task Manager” into the Window search box. 

If you can see “More details” at the bottom left of the windows that opens up, click on this to get the full details. You can then click on the column headed “Memory” to sort the programs in order of the amount of memory they are using.  Note that the memory being used by a program can be listed under the section named “Apps” and also under the section named “Background Processes”. As you can see in the image below, Evernote is using over 500mb of my memory even when it’s supposed to be closed, and Outlook is currently using nearly 162mb.

Even though closed, Evernote and Outlook are using 505.7mb and 161.8mb respectively.

You may find other programs that behave like Outlook and Evernote in this respect, and you may also get some insight into how much memory your other programs use in their normal functioning. Internet browsers, for instance, can use a lot of memory, Chrome, in particular, has got itself a bit of a reputation in this regard. You can easily get Chrome to use 700mb of memory with just half a dozen tabs open. Chrome does, at least, release the memory it has been using when you close it.

Don’t get too hung up on keeping memory use as low as possible, though. The only time that memory use becomes a problem is if your system currently needs more than it has available. At that time, it will write some of the memory’s contents to disc in a process called “paging”. This is what slows things down, but it’s usually not noticeable. If, however, you’ve only got, say, 4gb memory, and you can make a cup of coffee while you are waiting for something to open up, then you may benefit from closing un-needed programs in the way described above instead of just clicking on the “X”.