New iMac really slow 2017

Some observations about Free RAM memory and system performance.

1. When you ran the Etrecheck report, you hadn't rebooted your system for 10 days.

In my experience using OS X Yosemite, El Capitan, and macOS 10.12 Sierra, free system RAM continues to decline the longer the system runs without rebooting. Call them memory leaks, badly-written apps that don't release resources when closed, or the phase of the moon, but it continues to happen. Rebooting doesn't fix the cause of the problem, but it makes it go away for a while.

2. More than 3 GB Available RAM would seem like plenty, but that's not the key number to watch. Regardless of your system hardware configuration, at least since OS X 10.9, I've observed that laggy performance and 'beachballing' becomes especially noticeable when Free RAM reported by Etrecheck dips well below 100MB. At least, that's when I begin to notice it on my Macs with my apps. Your system shows 28MB Free RAM on the Etrecheck report. Rebooting your system more often will restore the Free RAM for a while. More system RAM (not a possibility with either of your Macs) doesn't 'cure' the problem, it only makes it take longer to become apparent.

3. Chrome is a resource hog. Each new release gets a little bit better, but it's still a hog.

4. A completely clean OS install, without transferring anything from old Time Machine backups, might boost performance. You have plenty of free hard disk space. You might create a 2nd partition and give it a try.

Just to add another perspective:

I find the slowness of 5400 rpm drives unacceptable; they are about 30+% slower than the standard 7200 rpm drives in 27" iMacs. This means that anything you do will take about one third longer. I've experienced that twice: once with a new Mac Mini which I decided to sell at a loss after 2 months and the other was an MBP which, fortunately, was upgradeable, so I replaced the drive with an SSD.

A simple solution for you might be to get an external SSD in a USB 3 enclosure and use that as your boot drive (using the internal as a backup storage area possibly). Or, sell your iMac (being covered by a warranty will be of great help with that as buyers do not have to worry about any problems).

And, you might want to check this explanation of how RAM is being allocated and used by the OS:

Use Activity Monitor on your Mac - Apple Support

With a machine this new you should be contacting Apple Support (link top right) and getting their help. It's entirely possible that you have a hardware issue that no amount of speculating on this forum will fix. Do not delay doing this - Apple are willing to give full refunds to unhappy customers if they report their concerns promptly enough. Even if they won't do this after 2 months you will probably be able to get a replacement machine.

I suspect that it's quite possible that this "loaded it from Time machine as a copy of my MacBook Pro", if it's literally what you did, is the cause of your issue. In your position, I would, testing at each stage:

Create a new user login, restart and see if the same problems affect the new user.

Resart in Safe Mode

Use safe mode to isolate issues with your Mac - Apple Support

Reset the SMC and NVRAM:

https://support.apple.com/en-us/HT201295

apple reset nvram

then do a wipe and reinstall of the operating system:

How to reinstall macOS - Apple Support

leave it overnight to finish indexing then and test its behaviour with native apps like Safari and Text Edit. If it was not okay I'd then contact Apple Support (Link to right). If it was okay i'd install necessary third-party apps and recover documents but not settings from TIme Machine.

C.

macOS spends several hours building indexes and caches, syncing files with iCloud, etc. when it is installed or updated. The 23 mdworker processes currently running suggest that this is the problem with your new Mac. If you have switched Filevault 2 on/off this will also cause the machine to run slowly while it does the considerable mount of work involved.

Leave the machine plugged in to the mains for a day or so, temporarily set the power settings to 'don't sleep', and be patient.

C.

When is the iMac slow and what model of MacBook Pro are you contrasting against?

The baseline iMac ought to be faster than a non-retina MBP, but if compared against a retina MBP the iMac may feel slower since the baseline 21.5" iMacs still use cheap high capacity HDDs while rMBPs come with SSDs on all models.

The CPU clock speed only indicates how fast a computationally intensive application will run once it is already open. The file/application opening however is limited by your drive speed as a file/app is read into memory. Your iMac has a 5400rpm HDD that runs at something like 85MB/s with delays to find a files measured in milliseconds. In contrast PCI based SSDs such as used in the rMBP run at >600MB/s with search delays measured in microseconds.

If you want large files to open just as fast on your iMac as on your laptop you will need to get an SSD for your iMac too. Using an external Thunderbolt or USB3 SSD drive as your boot volume is one option.

I gonna my own sentiments here.

Here's the BIG issues with all, but the topped out, slimline, 21 inch screen iMac.

The new, slim profile 21 inch screen iMacs that Apple offers now are, IMSO, "downgrades" from the previous 2009 thru 2011 21 inch iMacs models.

The newer, slim profile, "slimline", 21 inch screen model iMac are, basically, sealed up, glued up, basic computing appliances, now, with only the "top of the line" with all the top options (top i7 CPU, 16 GBs of RAM, 256 or 512 SSD) being the only viable option to use as a standard to medium professional grade, work related, iMac with just enough power for professional and creative use.

There is nothing in the new 21 inch screen iMacs the is user upgradeable OR serviceable, any longer.

Slower laptop 5400 RPM hard drive/fusion drives, limited RAM (the 2010, 2011 i5 CPU models and higher could take up to 32 GBs of RAM).

The newer 21 inch screen iMacs are limited to just 16 GBs of RAM.

A 5400 RPM laptop standard hard drive is 33% slower than the normal "standard" desktop 7200 RPM hard drives, making both read and write speeds to the drive 33% slower, in addition to other system delays.

Also, like laptop models, the newer 21 inch screen iMacs no longer use dedicated, discreet and independent GPUs.

The new 21 inch screen iMacs use the "so-called" integrated (soldered) Intel Iris ”Pro" GPUs, now!

Meaning that in any of the newer 21 inch screen model iMacs, if you get one with the max 16 GBs of RAM, a little bit to quite a bit of that installed RAM is being used for the GPU's VRAM, now.

Meaning that the GPUs in these newer 21 inch screen model iMacs is stealing away physical RAM, for use by the GPU, that could be needed for any other possible RAM intensive tasks depending on the apps being used or what combination of apps is being used together.

This would not be as big an issue if you could install more than 16 GBs (which there is no way to do this any longer as Apple has soldered every single component to the logic board, now).

8 GBs of RAM is the new base RAM "MINIMUM" for Mac OS versions, now.

So, 8 GBs of RAM is not a lot of RAM for both the OS and any running applications.

To get a better performing iMac, now, you would have to spend the money for all of the top end options for the new 21 inch screen model iMacs to ensure some longevity and "futureproofing"

OR

You would have to graduate up to the more expensive 27 inch screen iMacs that still have 7200 RPM hard drives/fusion drives, independent GPUs and user installable/upgradeable RAM.

I am NOT a big fan of these newer 21 inch screen iMac models, at all!

Other than a top shelf version 21 inch screen model, the other 21 inch screen model options are like a Mac Mini with a screen, now, or like a laptop/desktop hybrid, sealed up appliance.

IF you have had this iMac for longer than 14 days, then sell it and get as much as you can for this iMac and go for a totally option maxed out 21 inch screen iMac with either the 256 or 512 GB SSD.

To greatly improve the speed and performance of your 2014, 21 inch screen iMac, you are going to have to spend some significant more cash for this to happen.

Purchase an externally enclosed USB 3.0 or Thunderbolt connected SSD.

Format the SSD and then purchase data cloning software, like Bombich Software's CarbonCopyCloner or Shirt Pocket's SuperDuper to make a bootable clone of your current system to the SSD and boot and run your iMac, exclusively from the externally connected and enclosed SSD.

Your iMac will run A WHOLE LOT FASTER from an externally connected and enclosed SSD!

This is the only way to make these newer slimline, 21 inch screen iMacs faster.

You can either opt to use your internal iMac's hard drive to just store data OR purchase, yet, another external USB 3.0 or Thunderbolt connected 7200 RPM mechanically spinning hard drive to use as your primary data storage and data backup.

If you are from the U.S., here is a good Mac/Apple source for external SSDs and standard 7200 RPM hard drives here.

https://www.macsales.com/

You can call them to speak with a sales/technical rep or contact by email.

Good Luck!

Call them memory leaks, badly-written apps that don't release resources when closed, or the phase of the moon, but it continues to happen.

In fact it's none of these and you are barking up the wrong tree. Sierra is designed to use all available RAM in ways that enhance performance.

C.