Memory is Not Storage – Trouble-shooting Your System

I found myself giving bad advice recently – which I hate to do – and it started with this panic email which I misinterpreted.

I have been working on a 10-minute video for the last three weeks. I got a message that said there wasn’t enough memory to save. There next thing I know, everything disappeared: library, project and event.

I want to focus on the phrase: “not enough memory to save.” Because, far too often, when you ask for help, if you don’t understand what this phrase means or use it incorrectly, more knowledgable computer geeks will trouble-shoot the wrong thing. (This was my mistake.)

• “Memory” refers to RAM. When you turn your computer off, everything in RAM disappears. We measure RAM in GB.
• “Storage” refers to your hard drives (which, in this case, includes SSDs). Storage retains your data even when the power is off. We measure storage in TB.

The difference between these two is crucial.

Image courtesy of Apple Inc.

RAM is always stored inside your computer. In the case of Apple silicon, it is stored on the same chip that holds the CPUs and GPUs.

If you are “out of memory,” it means that your applications and their associated data have filled your available RAM to the point that further processing is not possible. While many applications take advantage of all the RAM your system has – Adobe immediately comes to mind – Apple has created a process called “swapping” such that, as RAM fills up, parts of your data are stored (“swapped”) to your hard drive, so that the application keeps functioning. Swapping slows things down, but doesn’t prevent operation.

While “out of memory” errors were common in the past, the speed of Apple’s internal SSD storage and the efficiency of Apple silicon have made these types of errors far less frequent.

Image courtesy of Cookie Cutter, via Pexels.com.

If you are “out of storage,” it means that you have run out of room on your hard disks to store files.

This can be a significant problem because many applications – Keynote is a good example – make a copy of a file to include any changes before deleting the existing file. If storage capacity is nearly full, the application can’t create those temporary files and everything grinds to a halt.

NOTE: For actual spinning hard drives, it is a good idea to always reserve 20% of total storage as free space. The fuller a spinning hard drive gets, the slower it goes. This restriction does not apply to SSDs.

If you don’t have any additional storage you can save that file to, you will lose all your changes and, potentially, the initial file; depending upon how the application handles files.

While I don’t generally worry about memory errors, I am constantly checking my storage to make sure there’s enough room for my next project. This is another good reason to use external storage for media and projects. You can quickly add capacity as you need it.

If you have problems with your system, keep this distinction in mind so that we don’t trouble-shoot the wrong thing.