iMac grinding to a halt
My iMac 2012 has a 3TB Fusion Drive, and has recently slowed to a crawl, taking seconds to respond to a mouse click. What’s wrong with it?
Before looking for software solutions, ensure you’ve got ample free storage space and run hardware diagnostics to check your Fusion Drive in particular. Third–party utilities such as DriveDx from bit.ly/ ml192drivedx or TechTool Pro also look at “wear” in the SSD component of a Fusion Drive. Memory used in that has a fixed number of times it can be erased and rewritten before it stops working. Fusion Drives with small SSDs, less than 100 GB, which are used intensively can wear out in less than their anticipated 10–year life, then require replacement.
If both components in your Fusion Drive appear healthy and not worn out, and there’s plenty of free space, you can turn your attention to software which could be doing this. Traditionally, the next step would be to clean re–install macOS, which could bring resolution when you’re still running Catalina, although it’s less likely to be of any benefit on a more recent Mac running Big Sur or Monterey, because of their sealed systems. Running EtreCheck from etrecheck.com can help pinpoint any software problems.
As your Mac is no longer capable of running a recent version of macOS, and repairs are becoming increasingly difficult, consider whether this wouldn’t be a good time to upgrade to an M1 model. Apart from its faster hardware, an internal SSD would bring huge improvements in speed.