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swandy

macrumors 6502a
Original poster
Oct 27, 2012
987
322
I have a 2019 21.5" iMac with 8GB of RAM. Everything on the Mac side (running Big Sur) runs fine - including the games I have downloaded from Apple Arcade. However, I also run Windows 10 under Bootcamp and that seems slow to me as far as initial startup and starting applications. I updated the video drivers and am able to run Doom 2016 and Doom Eternal pretty well through Steam - though the startup of Steam and the Doom apps is again slow.
Would trying to upgrade my RAM from 8GB to 16GB help? When I purchased the iMac I researched running MacOS on only 8GB and was mostly favorable. But that was before Apple Arcade and I certainly did not take into account running Windows 10 under Bootcamp.
Any suggestions or advice would be appreciated on whether I am waiting my time and money on the memory upgrade. Thanks.
 

opeter

macrumors 68030
Aug 5, 2007
2,709
1,619
Slovenia
Yes, in most cases, it would be worth to upgrade to 16 GB (2x8GB) or even more (2x16GB), if you get good RAM price. Because you can have more stuff/application open at the same time etc.

Which model is it?

iMac 21.5-Inch "Core i3" 3.6 (4K, 2019) 3.6 GHz Core i3 (I3-8100)
iMac 21.5-Inch "Core i5" 3.0 (4K, 2019) 3.0 GHz Core i5 (I5-8500)
iMac 21.5-Inch "Core i7" 3.2 (4K, 2019) 3.2 GHz Core i7 (I7-8700)

You computer should have one of the Radeon Pro 5xx series of graphic card or better (Vega Pro series).
 

mj_

macrumors 68000
May 18, 2017
1,618
1,281
Austin, TX
What kind of permanent storage does your iMac have - SSD, Fusion Drive, or HDD?
Based on your description it sounds like you don't need more RAM but faster storage instead.
 

usagora

macrumors 601
Nov 17, 2017
4,869
4,456
Just to be sure you realize, the 21.5", unlike the 27", doesn't have an exterior access panel to upgrade the RAM. You have to remove the display and also disassemble much of the inside in order to upgrade the RAM:

 

4sallypat

macrumors 601
Sep 16, 2016
4,034
3,782
So Calif
I have the a base 2019 4K iMac and it has 8GB of RAM.
The processor & RAM are very quick - the only slow bottleneck issue is the HDD or fusion drive.

Since I am not adept at breaking open the glass seal with a tape cutting tool and replacing the double sided tape, I decided not to gain entry into the iMac.

Instead I added an external SSD (Thunderbolt) that has my bootable OS and apps on it.
This setup runs super quick and snappy!

FYI wiping the internal slow spinning HDD and now use it as an archive / storage drive.
IMG_6792.jpg
 

swandy

macrumors 6502a
Original poster
Oct 27, 2012
987
322
What kind of permanent storage does your iMac have - SSD, Fusion Drive, or HDD?
Based on your description it sounds like you don't need more RAM but faster storage instead.
1TB Fusion Drive. And what you say has been suggested in another forum post. The poster claimed that the HD that Apple used in their 2015-2019 iMac did not have good specs. Might look into that also.
 

swandy

macrumors 6502a
Original poster
Oct 27, 2012
987
322
I have the a base 2019 4K iMac and it has 8GB of RAM.
The processor & RAM are very quick - the only slow bottleneck issue is the HDD or fusion drive.

Since I am not adept at breaking open the glass seal with a tape cutting tool and replacing the double sided tape, I decided not to gain entry into the iMac.

Instead I added an external SSD (Thunderbolt) that has my bootable OS and apps on it.
This setup runs super quick and snappy!

FYI wiping the internal slow spinning HDD and now use it as an archive / storage drive.
View attachment 1774661
It's an interesting idea, but I have more issues running Windows 10 under Bootcamp than when I just run MacOS. And from what I have read there is no supported (one idiot called it "illegal") to install Windows under Bootcamp on an external HD. And Windows 10 - it's initial startup and then starting certain apps - is where most of my issues exist. Thanks anyway.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
29,193
13,247
You'd have to COMPLETELY disassemble a 21" iMac to add RAM.
It's NOT a job you want to try. There's a very high possibility something could get broken inside.

That said, if you have a 1tb fusion drive, it could be slowing down the Mac somewhat.
A possibility is to add an external USB3 SSD.

For more speed, you could get a USB3.1 gen2 SSD (such as the Samsung t7).
Or, get an nvme blade SSD and a USB3.1 gen2 enclosure, and put it together yourself.
 

mj_

macrumors 68000
May 18, 2017
1,618
1,281
Austin, TX
1TB Fusion Drive. And what you say has been suggested in another forum post. The poster claimed that the HD that Apple used in their 2015-2019 iMac did not have good specs. Might look into that also.
The problem with a Fusion Drive is that Windows will run completely and in its entirety on the slow hard disk drive portion of the Fusion Drive and not utilize the much faster SSD at all. Which means you are effectively running Windows 10 off a dead-slow 5,400 rpm hard drive. Your problem isn't RAM at all. Your problem is 100% your slow storage subsystem.
 

alien3dx

macrumors 68020
Feb 12, 2017
2,193
524
WORTH IT , but i ask shop to do it , 2017 version.Upgrade the platter to ssd same time
 
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