Late 2015 iMac extremely laggy. Upgraded 1tb SSD and upgraded i7 CPU

I am not sure why a another posting is saying " iMacs are not upgradeable " as you have successful upgraded the SSD and RAM

If what was meant was to upgrade to macOS 13 Ventura, then I would agree

Computer Qualifying for macOS 13 Ventura 

Which seems for another site to be possible >> https://everymac.com/systems/apple/imac/specs/imac-core-i7-4.0-27-inch-aluminum-retina-5k-late-2015-specs.html#:~:text=This%20model%20is%20powered%20by,memory%20controller%20(dual%20channel).

IslandStylin wrote:

I am officially at a loss on how to fix the speed of my late 2015 imac. I have opened this computer and added a SSD, which is a Samsung SSD 970 EVO 1TB. I have updated the CPU to an Intel 4ghz i7.

As of this morning, I've updated the Ram from 16gb to 32gb Crucial DDR3L 8gb sticks.

None of this has helped. The Kernel_task revs up randomly and I'm 'pulling out my hair out.' I don't understand what can be causing this. I use this machine mainly for the internet and Adobe Suite. When I first updated the hardware there was no issue at all. I was able to edit video and photos fine. Now...It's been abysmal to say the least. I am considering rolling back my OS as perhaps that may be the issue? I am on Monterey and think it may be the issue.

When I first completed the hardware install the computer started up in a flash. Now it takes upwards of 2-5 minutes before I see the users. I can maybe ditch chrome and use another browser if that's the problem? Chrome has 10 tabs opened currently

I have tried clearing the cache in the past and haven't seen a vast improvement.

While I was running this test the kernel_task was at 500%. In the report it doesn't show that. I was having a very laggy time even typing out this post.

Needless to say, I am lost. I would be so appreciative for any advice this community would lend me.

<EtreCheck.log>

Although the computer is reporting the latest version of Monterey 12.7.4.

And, the internal Drive has been replaced with the Samsung EVO SSD Drive

Q - SSD too slow - SSD is showing poor performance.

A - The drive is still being reported as slow

Q - Heavy RAM usage - Apps are using a large amount of RAM.

A - Check in your Startup Items and Launch Daemons .Remove any not essential application from Starting when the computer Starts Up

Q - Unsigned files - There are unsigned software files installed. These files could be old, incompatible, and cause problems. They should be reviewed.

A - Self explanatory

Q - System modifications - There are a large number of system modifications running in the background.

A - Anytime there are large numbers of System Modification the Operating System may become less responsive and lag

Follow on from the Read and Writes Speeds in the report

Write speed: 967 MB/s

Read speed: 1415 MB/s

From a larger Samsung EVO 2 TB SSD

https://semiconductor.samsung.com/consumer-storage/internal-ssd/970evo/#:~:text=Next%20level%20SSD%20speed,writes%20than%20the%20previous%20generation.

Of specific interest

" Performance may vary based on SSD’s firmware version, system hardware and configuration. Performance measurements based on IOmeter 1.1.0.

Write performance measurements are based on Intelligent TurboWrite technology.

* Test system configuration: Intel Core i7-7700K CPU @4.2GHz, DDR4 2400MHz 32GB, OS-Windows 10 Built 10240, Chipset–ASUS PRIME Z270-A

* The sequential write performances after TurboWrite region are: 300 MB/s(250GB), 600 MB/s(500GB), 1,200 MB/s(1TB) and 1,250 MB/s(2TB). For more information on the TurboWrite "

You may need a Samsung Firmware update to get a better performance for this drive

iMacs are not upgradeable. You can see that in the EtreCheck file system test. It is failing and timing out after 2 minutes. Normally that should take 30 seconds or less.

When the kernel_task goes over 500%, that is the operating system throttling the hardware. The idea is to keep the computer running for long enough to make a backup before complete failure.

You'll need to purchase a new computer.

PRP_53 wrote:

I am not sure why a another posting is saying " iMacs are not upgradeable "

Because they aren't?

Relatively speaking, iMacs are somewhat upgradeable in the sense that some of them (usually the 27" models) can have their RAM upgraded by the user. In other cases, iMacs can have their RAM upgraded by Apple. In this case, the RAM in the OP's iMac is already at maximum.

The hard drives in iMacs have never been upgradeable. In rare cases, with very specific aftermarket parts, some people have successfully upgraded certain older iMacs. But no one should ever recommend that course of action. In mosts cases, any such attempt will render the computer inoperable, as in this case.

you have successful upgraded the SSD and RAM

Not at all. The hardware is running in "damaged crisis mode" by spiking kernel_task to throttle the performance. The SSD is not functional. Don't read too much into the read and write speeds on the EtreCheck report. Most of the time, the computer isn't reading and writing those kinds of large files. Most of the time, it is creating and deleting small files and directories. That's what the EtreCheck file system test is designed to check. The OP's computer failed that test. That means the SSD is not functioning properly.

At least the OP will be very happy with the performance of their new Apple Silicon Apple computer. Hopefully they don't make the standard hard drive mistake. All too often, people buy new Macs with tiny hard drives so they can save $200. Then they spend more than that on some junky, incompatible external hard drive. This leads to no end of disappointment and frustration. As the OP has already attempted to upgrade an iMac, they are likely at high risk for falling for this trap. Don't do it! Invest in a big SDD and enjoy your new computer.

Hi IslandStylin,

Thank you kindly for getting back to us, after all your efforts. Wonderful to know the problem errors seem to have been dealt with, and your Mac seems to run normally, when Chrome and Adobe are not in use. Am very grateful to those who gave their time to read and respond to your initial Etrecheck report.

Re: "I am unsure how to figure out what is essential and what is not in the System mods and unsigned files. I feel like perhaps the update to Monterey is where the problem lies".

Sorry I don't have the expertise to comment on this "updated" Etrecheck report, or to advise about the system mods or unsigned files.

Re: "I feel like perhaps the update to Monterey is where the problem lies. The only problem for me is that I can no longer run Premiere Pro if I downgrade past Monterey. At least they no longer support that."

Seems upgrading a 2015 iMac to MacOS Ventura is not possible.

If macOS Monterey 12.7.4 is installed, the update itself shouldn't be a problem.

IslandStylin wrote:

Do you think it could be operating system-related? If I downgrade the problems might disappear?

No. iMacs are not upgradeable. It's true that many people have successfully replaced hard drives with SSDs in older iMacs. But many people have also failed to do that.

I did that upgrade myself to an old 2010 or 2011 iMac and it worked OK. I was still disappointed with the end result. It still seemed more "pokey" that I would have expected. It was difficult, expensive, and ultimately disappointing. And I was one of the successful ones.

Don't read too much into any particular EtreCheck report. It's a diagnostic test like any other. Any "failure" result on such a test is valid. Any subsequent "successful" tests are not. It may be that if you only run Finder and EtreCheck, then you'll experience no more kernel_task throttling. But is that really a solution?

Wondering which MacOS Monterey version is installed on your Mac:

Eg: see: What's new in the updates for macOS Monterey - Apple Support

When you put certain details into context - maybe

To avoid any further possible conflict of opinion.

It is better if the other contributor take charge of the latest Etrecheck Report and provide their guidance