The 2019 27” imac is still a great and powerful mac to buy in 2020. Although the overall design
feels a bit dated it still has an industry leading 5K display and fast processors in an all in one
package. The only thing that can hold it back is the amount of Ram it comes with. How do you
know if you need more ram, how do you install it, and what is the benefit? Lets find out.
Hey, Im Jerry and I just got this refurbished iMac from the Apple Store with a 6 Core i5,
radeon 580x and an insufficient 8gb of ram. Luckily, the 27” imac still lets you easily
upgrade the ram which is accessible through a back side hatch. But, do you really need to add ram?
If you open activity monitor and look at the memory tab you can see down at the bottom the
Swap Used. Swap memory is when the system runs out of real Ram and Swaps the memory, temporarily,
to the hard disk, which is much slower than your system ram. When the computer needs that memory
again it needs to read it first back into the real ram before your computer uses it.
Over time, as you open and close apps and documents some things will stay in the ram.
You have probably seen some apps start slower than usual if the computer has
been on for a long time or maybe you start seeing some beach balls. A reboot will
usually fix this temporarily because it flushes everything out and starts the build up again.
Just as a couple of examples we can run 2 tests with the built-in 8GB of memory that
came with this imac, starting with geek bench.
As we run through the Geekbench test you can see that the Used memory goes quite high
but we are not really adding to the swap memory, which is good,
but it is also self limiting what it can do with the limited memory.
The final results of the test on this imac with 8gm of ram
is a single core of 934 and a multi core of 3930.
Another way to test the memory usage is by exporting a video in premiere pro. I am
going to export a 90 second clip of my previous video. There are no pre-rendered files and we
are going to use the standard youtube 4k preset. I will start a stop watch to record the speed.
You can see right away that the swap usage jumps,
meaning it is relying heavily on the hard drive for temporary memory.
And this test completed in 1:48 seconds, which is
slower than real time and it uses well over 1.5 GB of swap memory.
Now I have here this OWC 32 GB kit that I am going to install into this imac
along with the original 8GB for a total of 40 GB of memory.
To do this you need to lay the imac on a soft flat surface. Above the power connector
is a small button that needs to be pushed in to release the memory hatch on the back of the imac.
This does take a little bit of force. On the back of the hatch there is a small diagram but what
you need to do is push the 2 gray tabs toward the center and the ram tray will spring out.
Now you can add the additional memory modules along with the factory modules.
When done, push the memory tray back in until it clicks and replace the hatch.
Now we are back up and running with a total of 40GB of memory. We can open activity monitor
and run the same geekbench and Premiere tests we did before and see if the performance improves.
Right off the bat you can see that we are not using
any swap memory and lets start the geekbench test.
With more memory geekbench is not being limited or using swap. So the results
on the same imac now with 40 GB of ram are 994 for single core and 4543 for multicore.
So a small bump on the single core and about 15% on the multicore which isn’t bad.
Now lets export the same 90 second clip as we did before,
now with 40gb of memory. You can see that the memory usage is going
up but the swap is staying at 0. The final export time with 40GB of memory is
1:23 seconds. Compared to the 1:48 seconds of the first test that is about a 23% improvement.
So although not a staggering difference in this imac there were some clear performance
improvements. 40 GB may seem like a lot for some users who do not edit videos or
perform other high performance tasks but you will see a big improvement in overall computing just
jumping from 8 to 16 GB. When the system does not need to keep moving memory back and forth
between the ram and the hard drive you will see faster app opening and less beach balls.
If you are looking to upgrade your iMac’s memory or have questions about it let me know
below. Again, I rreally believe that refurbished macs are a great way to save a lot of money so
be sure to check out my refurb 16” macbook pro unboxing video and Ill see you next time.