16 GB unfied memory in M4 Mac Mini vs 16 GB RAM in mid-summer 2017, 27-inch iMac

I have re-read your original post and stand by my contention that an extra 8GB RAM will have negligible effect for an insane price. Simply bumping it up to 32GB almost doubles the price of the mini!

You need to organise what sounds like a chaotic system of working. Like anything else, computers deserve treating with respect.

The way you describe it, even 64GB would struggle.

.I would recommend at least 24GB of RAM for the M4MM based on your needs Also ensure you buy adequate storage, at least the same amount as your old iMac. Remember current Macs are NOT upgradeable for either RAM or storage!!!

DO NOT delete any emails off the old machine. To migrate from the old iMac to the new MM please follow the instructions below for a smooth and trouble free upgrade:

·       Always connect your old Mac's Time Machine External Hard Disk prior to startup, this will allow a migration from your TM backup and it will be dead simple! When you start the new Mac for the first time it will startup Setup Assistant (SA), SA will get to a point where it asks if you are migrating from another computer, select Yes and follow the on-screen prompts and it's done! It is that simple! This is the easiest, quickest and most reliable method to migrate from the old Mac to the new Mac is to simply connect the old Mac's Time Machine External Hard Disk to the new Mac using a USB cable before you turn on the new Mac. 

·       NOTE 1: You will likely need a USB A to USB C adapter, you can find them on Amazon for $10 or less. Something like: USB to USB C adapter

·       NOTE 2: If you have already done SA on the new computer then simply connect the Time Machine External Hard Disk using a USB cable and launch Migration Assistant (MA) which is located in Applications - Utilities - MA. Then follow the on-screen prompts.

·       The ONLY difference between MA and SA is MA will create a new user account that you need to log into.

Both SA and MA migrate applications (not 32 bit apps), data files & settings. They do not migrate Mac OS itself. Some professional apps such as Adobe and Microsoft apps may require re-installing their apps as they will not allow them to be migrated. As long as you kept the security keys for installing their apps, it is not an issue. 

Finally, my recommendation is not using Wi-Fi when doing Setup Assistant or Migration Assistant. Why, it simply fails in a lot of the cases reported in these forums. A wired connection is more reliable and the last thing you need is a failed migration when there are safe methods readily available. Please read and follow the directions in Setup Assistant and Migration Assistant. If you do not have a Time Machine backup of the older Mac then create one!If you are not aware of Time Machine, please read Back up your Mac with Time Machine and finally if you need an External Hard Disk to use as a Time Machine External Hard Disk then many experience users on these forums prefer the OWC Mercury Elite Pro due to it's reasonable price, high level of quality and ease of use. 

GummoMarx wrote:

Putting that aside, here's my question:

Assuming I do not delete email and do not close browser windows,

1) would 16 GB of unified memory on a new Mac Mini M4 significantly speed up and make Apple Mail and my browsers work more efficiently

OR

2) should I get 24 GB of unified memory?

1 - It may or may not. Your "speed" in Apple Mail is more dependent on email server & internet speed as well as the relatively low performance of your Fusion drive. A new Mac Mini M4 (with unified RAM + onboard SSD) will dance circles around your 2017 iMac with a Fusion drive. But you have no control over the speed of the email servers & the variability of your internet download speed. Regarding your browser, you are taxing the app & your internet connection by having so many windows open; it is good practice to minimize the number of open browser windows/tabs.

2 - It would be better to get 24GB unified memory due to the apps you are currently using and for future proofing since the trend is that each new release of macOS & Adobe apps requires more & more system resources.

1) Yes. One of my MBP 2017 has 16GB RAM but it runs slow now with Monterey.

2) If you have budget, please get 24 GB of unified memory.

Doubling the RAM to 32GB has little effect so I can't see any point in getting 24GB.

I have got an almost identical iMac (that suddenly died yesterday ☹️) but it has only 8 GB RAM.

I have also got the base model M2 mini which also has 8 GB RAM

My base M2 is at least twice as fast as the iMac (used to be!) so just imagine how fast the new M4 mini will be with its speedier processor and 16 GB RAM.

It should be around 3 times faster than your iMac!