SSD in early 2009 iMac Question

I think I might like to REPLACE THE HDD WITH an SSD. Is an SSD even going to help?

Yes. Given the symptoms you describe that Mac's hard disk is operating in a state of failure.

My concern is what I’ve read regarding the fans and temp. sensor. Is this going to be a problem?

Not if you get an SSD from OWC.

Having said that you need to take into consideration the age of that Mac and the likelihood that you are certain to encounter increasing inabilities to perform some fundamental actions that will require a newer macOS version. Mail seems to be a problem lately.

It getting a little late in the game to be upgrading that old of an iMac. You would be better off saving and putting that money towards a new or newer Mac.

If you wish to upgrade it to an SSD, see > https://eshop.macsales.com/shop/ssd/owc/imac/early-2009

FWIW the sensor thingy, wasn't an issue until the Late 2009 and later models.

https://eshop.macsales.com/blog/2751-proprietary-cable-can-put-the-brakes-on-upgrading-late-09-imacs

Please run EtreCheck and post the report it generates here under "Additional text". Review my comment regarding any installation of antivirus or Mac cleaner apps. They will seriously slow things down and must be removed.

Thank you for posting the EtreCheck report. My comments follow. Perhaps someone else may have something more to suggest. I would not remove Malwarebytes. It is useful and it causes no harm. You: (1) have an older computer that may be coming to the end of its life. Hard drives do not last forever and tend to get slower as they die. (2) 8GB of RAM should be adequate for this operating system and it can not be user upgraded. (3) You have an old slower mechanical drive. Replacing with an SSSD is not really practical. (4) In looking at your installed apps, I see Ad Guard. I am unfamiliar with it. It may be problematic. You might try removing it to see if that improves your speed. The question is - does it actively run in the background? If so, that may cause slowness. (5) Chrome browser is a RAM hog. Consider replacing it with another one like Firefox. Given the age of this computer, remember all computers eventually die. If replacing it is a cost problem, you might look at buying a reconditioned Mac from Apple. They are some good buys.

I think that changing your HD might not b feasible in this model. You only have 8GB of RAM, which is minimal, but adequate. It is not user gradable. This computer is old and its hard drive might be starting to fail. I offer the following suggestions which might be useful to you in dealing with a slow computer. Often times there is a specific cause and other times any of the following actions may be helpful. They are “maintenance” steps which are often ignored.

·      It is important to occasionally restart a Mac. Ideally, once a week or more often. This does some system cleaning.

·      Regularly clearing the history of your browsers can help as all the data is stored in RAM. Clearing frees up RAM for system use.

·      Some people seldom empty their trash. If you haven’t, then do so. Also empty your email trash.

·      Some programs use a lot of RAM. (Like many Adobe apps.) When using then, close any other apps not being used.

·      Doing a restart in the safe mode can clear a number of problems. This is done by holding down the shift key at start up. This process can take up to ten minutes while the computer is doing its maintenance and cleans the cache. You may then restart normally.

·      It is also a good idea to run the Disk Utility app. If it reports some issues, then rerun it repeatedly as needed until the final report is ok.

·      On some computers the problem may simply be that there is not enough RAM installed for RAM hungry programs that are being used. On your computer a RAM upgrade must be done by a qualified Apple service specialist. And there may be a substantial cost, IF they will even do it.

·      Last, and most important, you should remove any and all maintenance and anti virus programs. They will cause problems and will significantly slow your computer. Also, the Chrome browser is a known RAM hog, so you may not want to use it.

·      It is also very useful to download and install the free app EtreCheck. Be sure to enable full disk access and run it. Save the report. You can post the results here at the bottom under “Additional text”. It will tell us exactly what you have installed which might be problematic.

I hope these suggestions are helpful and enable you to speed up your computer.

It sounds like you've got it covered.