Time Machine impacting general response of computer

There are various issues that can arise.

A failing internal or external HDD is a good option, as can be the 8 GB / HDD iMac performance.

Add-on apps can get involved, too.

Please download and run (free) EtreCheck, and when the run completes share the report to the clipboard. Then open a new reply here, and press the additional-text button that looks like a printed page to get a text input box big enough to paste the hardware and software configuration report here, and paste and post that report here.

Please also post the output of DriveDx for the internal storage, and for the Time Machine disk. (That tool can’t display the error data for all the possible different sorts of external disks, but it can display it for enough.)

Time Machine goes to some effort to protect itself and its archives from modifications, and protections here have been increasing in newer versions, so I’d not expect direct deleting of files in a TM archive to even work.

Most likely, that backup disk is operating in a state of failure. Replace it with a new one, or one that is verified to be in working condition. One and only one backup disk does not comprise a robust backup strategy anyway. You can use as many as you like.

Can I delete some of the backup history on the external hard drive ...

No. That will corrupt TM's database thereby rendering the entire backup history worthless.

... or do I need to reformat the external drive and start over?

You can certainly do that. The drive may continue to work for months or years. Or, it may fail again in a very short period of time.

If you feel comfortable deleting some of your backup files from the past that may help the issue, although Time Machine is supposed to regulate itself for the most part. A full reformatting would probably alleviate the issue for you, but only until the backups reach the same point they're at now, again. The reality of using hard drives, both for internal drives and to backup to, is that they do not transfer quickly. Especially when the majority of the drive is already full, things can get really slow. Pairing this innate flaw with older hardware is a surefire way to get a terrible experience. My biggest piece of advice would be to schedule your Time Machine backups to be sometime at night, or when you're sure you won't be using the device, if possible. This way you won't experience any slow-down while using the computer, but your backups will still be completed. Your backups will probably still take a great deal of time to finish, but that behavior is to be expected, at least in my past experience, from older hard drive based Macs using Time Machine.

That's all I've got.

I hope this helps!

SniperJo12,

Manually deleting Time Machine backups is VERY poor advice as this action will brick Time Machine! Never ever manually delete a backup. Mr. Hoffman's advice is spot on, yours unfortunately is a good way to create even more problems for the OP.

It will destroy the Time Machine backups if you manually delete them. We have hundreds of instances where users have done this and have had to re-format their HD's and start over with Time Machine by manually deleting individual backups. This is why advising to manually delete Time Machine backups is not a good practice.

In addition, advising a user to use CMM is also poor advice. At best CMM is garbage, again we have seen hundreds (if not more) users post on these forums after using CMM and had CMM modify and damage Mac OS. CMM does absolutely nothing that Mac OS does not already do which makes it 100% worthless, as are the following types of other third party apps:

• Antivirus
• Cleaning
• Security
• VPN
• Maintenance

If budget is a concern you might consider this setup with a SSD:

I have a 4TB SSD for my Time Machine. The USB C adapter gives me 500 Mbs read and write speeds.

Otherwise the OWC Mercury Elite Pro in the size you need is an excellent choice as it's very reliable, inexpensive and has excellent customer support.

Just some food for thought.

SSDs are a great option if you're looking to upgrade your Time Machine Server. I would advise however, that you buy an M.2 NVMe SSD(s) instead of SATA ones. SATA drives are definitely much slower in terms of read and write, and yet, generally more expensive than their NVME counterparts. If you bought a Kingston, Samsung, Crucial, etc, NVMe SSD, and a USB/USB-C enclosure for it, you would be receiving much better value for your money. Even if your Time Machine would only be using around SATA speeds (because you're backing up an older Mac), an NVMe drive would be much better value for your money if an SSD is the route you decide to take, and allow for other uses of the drive in the future, that may benefit from those faster speeds. I have personally taken this path before and it's been great. I was also able to use the SSD in the enclosure as independent fast storage for other files, and one of my drives I even ended up using as the main drive for one of my computers. This flexibility for future uses of your drives makes NVMe drives the best option in my opinion, if you were to upgrade your storage.

What do you think?

I hope this helps!

It won't brick your backups if done carefully (hence my language "comfortable"). See this article. I'm not advising deleting files left and right, but carefully approached clearing of past backups will not cause any issues. I have no malicious intent responding to this thread, I am merely attempting to share any input I may have that he may find useful. I apologize for the confusion.

The link you posted is an advertisement for a garbage product that should never be installed on any Mac. As such it should be utterly disregarded.

Using it, or anything like it, will result in permanent and irretrievable data loss that will require completely erasing the Mac and — most likely — its Time Machine backup, leaving the user with nothing.

Just to be clear, the part of the article I am referencing does not advocate for the use of "Clean My Mac" in order to clear out the backups. It only requires Finder. You both are correct though, manually deleting backups may very well inadvertently cause drastic undesirable effects on your backups. I apologize for advocating for this idea without first, properly researching it. Thank you for the feedback.

SniperJo12 wrote:

It won't brick your backups if done carefully …

Backup archives are protected as part of macOS security, and modifications and deletions outside of Apple tools are generally blocked, as these modifications are something that malware will try.

Your welcome.

It is an advertisement and ought to be removed as a violation of this site's Terms of Use.