Why would Apple make a desktop in which the RAM can't be upgraded? 21.5-inch, Late 2015

As you've already been told RAM doesn't make a Mac run faster. The hard drive does. It looks like you bought the low end iMac that has on 8 GB of RAM and a 5400 rpm fusion drive. That limits your performance right from the start

Have you installed and run any "cleaning", "optimizing", "speed-up", anti-virus or VPN apps on your Mac? If you have that's another nail in the coffin.

Download and run Etrecheck. Be sure to give it Full Disk access before running.

Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

Copy the report

and use the Additional Text button to paste the report in your reply.

Then we can evaluate the report to see if we can determine the cause of the problem.

Based on deep history here with 21.5-inch iMacs introduced between 2012-2019, 95% or more of the complaints about "slow" prove to be the slow and under-spec mechanical hard drive Apple use in entry-level iMacs. That is why people are asking you for an Etrecheck report. That will show performance data that is the one thing that will confirm if the drive is your bottleneck.

I am sure that , if you took your car in for service because of a strange problem, you would prefer the mechanic use data-gathering hardware to diagnose the problem instead of guessing. Same here.

In case of the dreaded slow hard drive problem, you could never add enough RAM to fix that. Still there may be cost-effective options that do not involved a new computer or taking yours apart. With data, we can give you very specific recommendations.

Allan Jones wrote:

In case of the dreaded slow hard drive problem, you could never add enough RAM to fix that. Still there may be cost-effective options that do not involved a new computer or taking yours apart. With data, we can give you very specific recommendations.

A 21.5" Late 2015 iMac would have shipped with a 1 TB (5400 rpm) HDD, a 1 or 2 TB Fusion Drive, 256 GB of flash storage, or [Retina model only] 512 GB of storage.

Fusion Drives never included more than 128 GB of flash storage, but the 1 TB Fusion Drives in Late 2015 iMacs were especially miserly. They included only 24 GB of flash storage. If you had a 27" iMac with 32 GB of RAM, that meant that the SSD portion of the Fusion Drive wasn't even big enough to hold all the data the computer needed to store to go to sleep. But even on an iMac with only 8 GB of RAM, I can't believe that a reduction in SSD size from 128 GB to 24 GB did any wonders for performance …

https://9to5mac.com/2015/10/13/retina-imac-fusion-drive-flash-lol-are-you-serious/

At least these iMacs did have four USB-A (USB 3) ports, and two Thunderbolt 2 ports. So one could connect external SSDs either via

• USB 3 – easy, inexpensive; or
• A Thunderbolt dock – probably a TB3/4 dock connected via a TB3-to-2 adapter

The biggest gain would simply be bypassing an internal HDD or Fusion Drive in favor of an external USB 3 SSD.

Between Late 2009 and Late 2011, all 21.5" and 27" iMacs had four user-accessible RAM slots.

In 2012, iMacs got really thin, and lost their built-in optical drives. The 21.5" ones lost two of their four RAM slots, and the other two RAM slots got sealed in. You seem to have one of the few 21.5" models in which the RAM is not only sealed in, but soldered in.

As to why Apple sealed in the RAM in some years, and soldered in the RAM in others, I don't think anybody who is here knows.

NanaNuth wrote:

I'd like to upgrade the RAM in my computer, it contains a great deal of files now and operates slowly.

Before you draw the premature conclusion your Mac's performance is being constrained due to a paucity of RAM please review the following: Check if your Mac needs more RAM in Activity Monitor - Apple Support.

Summary: if the unitless "Memory Pressure" graph is frequently "red" then your Mac would benefit from more memory. If it does not, then it would not. It's that simple.

Good advice here already, just want to add that you can check your current RAM usage using a utility already on your Mac, you can find it here: /Applications/Utilities/Activity Monitor.app

take a look at the Memory Panel:

down at the bottom you will see a summary of available Physical Memory, and what is currently being used.

When Memory Used is larger than Physical Memory available, you will see that Swap Used: is making up the difference, and then you are actually using the hard drive for memory needs beyond the physical 8GB of RAM that you have installed. Thus, a faster hard drive with sufficient free space is helpful in keeping things running smoothly when you exceed the physical RAM usage. Nothing wrong with Swap space for memory, but it can be much slower if you have a nearly full and slow hard drive.

/Applications/Utilities/Activity Monitor.app might not be that easy to understand but it does show a wealth of information about what is using the most of the CPU and RAM resources available on your computer, so in addition to the other advice mentioned, it may give you some helpful info.

Have a look here if it is possible with your model: Install memory in an iMac - Apple Support

Apple doesn't. You can upgrade your RAM, you just have to do it at time of purchase. Why make that devision? Probably because it's in their plan to offer low end computers all the way up to very high end computers. You just have to do your research and understand where on that scale you're really buying from.

Hi there,

As mentioned on that page, your iMac model isn’t upgradable when it comes to RAM.

Upgrading your iMac RAM may not fix slow performances though.

Answers brought in this previous post may help you.

stumpy1946 wrote:

Apple doesn't.

Actually, they do make desktops in which RAM cannot be upgraded. None of the Apple-Silicon-based desktops (iMac, Mini, Studio, even Pro) support upgrading RAM after purchase.

Apple Silicon architecture depends on having all of the computing units share access to all of the RAM in a way that provides high-speed access to computing units. Higher-end chips have more computing units (especially GPU cores), but also more RAM-to-SoC bandwidth to feed them. E.g.,

• M1/M2 – Surrounded by 2 RAM dies. Maximum bandwidth: 66 GB/s (M1) or 100 GB/s (M2)
• M1/M2 Pro – Surrounded by 2 RAM dies. Maximum bandwidth: 200 GB/s
• M1/M2 Max – Surrounded by 4 RAM dies. Maximum bandwidth: 400 GB/s

Apple Silicon GPUs are "integrated GPUs" by the traditional definition – but the iGPU in a M1 Max or M2 Max has much higher performance than people traditionally associate with Intel integrated GPUs. That is in no small part due to the Max's high RAM-SoC bandwidth and the way it makes bandwidth available to its internal GPU cores.

You can upgrade your RAM, you just have to do it at time of purchase.

That's not what the OP means – or what most people mean – when talking about the ability to upgrade RAM. They're talking about the ability to take a computer that has less than the maximum amount of RAM, and add more RAM – possibly RAM from a third party – later.

By the way they likely designed it with 8 GB because in 2015 8GB was enough for most users who didn't want to fork out a couple of hundred $ for something they didn't think they would ever need. Have a look at Obtaining service for your Apple product after an expired warranty - Apple Support for how Apple's take on the useful lifespan of a computer.

well with the system on a chip they moved on to with their apple m1 and 2 chips then they seem to be moving in the opposite direction of your wishes

suppose you can give them a piece of your mind using their feedback channel

Feedback - iMac - Apple

NanaNuth wrote:

Yes, Geek Squad installed a pricey anti-viral program.

That's not good. Which one was it?

First, there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This documents describe what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community and Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support.  

There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   

Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.

There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is designed solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  

Also, unless you're using a true VPN tunnel, such as between you and your employer's, school's or bank's servers, they aprovide false secutiry from a privacy standpoint.  Read these two articles: Public VPN's are anything but private and Former Malware Distributor Kape Technologies Now Owns ExpressVPN, CyberGhost, Private Internet Access, Zenmate, and a Collection of VPN “Review” Websites. 

So uninstall that junk-ware according to the developer's instructions.

True, but not his model. Thanks for the recalibration.