CleanMyMac X

Hinder! Hinder! CleanMyMac (and all apps that claim to "speed up", "clean", "tune", etc. your Mac) are no good. They delete important system files to 'clear space' that doesn't become apparent until much later. They'll just slow your Mac down even more while cluttering the drive up with useless junk.

I recommend reading this excellent user tip - Effective defenses against malware and ot… - Apple Community

If you have concerns with your Mac being slow, you may want to review this article - If your Mac runs slowly - Apple Support

We can better help if you tell us:

1. the screen size of your iMac,
2. the processor type,
3. the currently installed macOS version,
4. and the kind of storage you have.

The first three are available from the opening screen of "About this Mac...'" under your Apple menu:

You can see the storage type by clicking the "Storage" tab to get this:

The options are:

• "SATA Disk" if you have the standard mechanical hard drive
• "Fusion" if you hav Apple's hybrid drive (SSD + Mechanical)
• "Flash Storage" if you have the factory SSD option.

Why is this important to this forum setting? We see hundreds of "slow" posts about 2012-2019 21.5-inch iMacs with the entry-level mechanical drives. Although mech drives worked OK with older original macOS versions, newer OS versions seem optimized for solid-state drives as in the Fusion and full SSD storage options.

There is also a crippled educational/institutional 2017 model with a slow laptop-class processor, made to sell cheap rather than provide peak performance. The cheap trick model does NOT have "4K" in its sub-model mane.

Our knowing the details of your iMac will help us see what options are available to improve performance, if any.

Things to note:

• Adding RAM (which is NOT user-accessible in 2012 and later 21.5-inch iMacs) will NOT change anything. Even some pro service providers will not add RAM to that model.
• Likewise, accessing the internal hard drive is equally challenging, with the risk of irreparable damage to the computer.
• ⚠️ There is a cost effective option which, when you replace this computer, can be of service to your next computer.

Once we know your details we can better advise you on what's is possible.

Never install any app that claims to "tune up", "speed up" or "clean up" your Mac. These apps exist for one reason: to separate the unwary and inexperienced user from their hard-earned money. At best they do very little, at worst, they can damage your OS installation and cause far more problems than they "solve".

I am so excited to hear if it helps on your 2017 Imac, uninstall CleanMymac?

Or it is another thing that have your iMac slowing down?