Should I have went for 40GB Ram instead of 24GB?

[Benz63amg]

i added 2 x 8gb OWC Ram to my 2019 iMac last night, all running flawlessly and I can see the iMac is currently using about 8gb ram out of the 24gb available in Activity Monitor, I’m a casual user. That’s with google Chrome running with a few tabs (YouTube, Facebook) and iTunes. There are 2 other users logged in on the iMac however there is no ongoing activity on the 2 other logged in accounts except for google chrome being open (just the application in the dock, no actual browser tabs open)

Since the IMac is using 8gb now, I have a feeling I should have added 2x16GB instead of 2x8GB, is Mojave known to be ram heavy?

On my previous iMac I had El Capitan and it had 12GB of Ram so I thought 24GB would be more than enough but my new 2019 iMac is using 8.5GB of ram after the ram upgrade with minimal things open so was 24GB a mistake? 40GB (adding 2 x 16gb sticks to the existing 2 x 4GB sticks from Apple was twice the price of 2 x 8Gb from OWC that’s why I went for 2 x 8GB)

 

[BJMRamage]

you are only using a third of the amount you have in there.
Personally I'd leave it be. in a year, if you feel it is starting to get "sluggish" then add more, it could even be cheaper then.

When I got my 2009 years ago I had just 2GB. I wanted to install more right away, but then thought if I let this ride for a while, once things start to get more bogged down, I can add more RAM (4GB total) and it'll give the computer a boost.

 

[patearrings]

Yes.

 

[casperes1996]

i added 2 x 8gb OWC Ram to my 2019 iMac last night, all running flawlessly and I can see the iMac is currently using about 8gb ram out of the 24gb available in Activity Monitor, I’m a casual user. That’s with google Chrome running with a few tabs (YouTube, Facebook) and iTunes. There are 2 other users logged in on the iMac however there is no ongoing activity on the 2 other logged in accounts except for google chrome being open (just the application in the dock, no actual browser tabs open)

Since the IMac is using 8gb now, I have a feeling I should have added 2x16GB instead of 2x8GB, is Mojave known to be ram heavy?

On my previous iMac I had El Capitan and it had 12GB of Ram so I thought 24GB would be more than enough but my new 2019 iMac is using 8.5GB of ram after the ram upgrade with minimal things open so was 24GB a mistake? 40GB (adding 2 x 16gb sticks to the existing 2 x 4GB sticks from Apple was twice the price of 2 x 8Gb from OWC that’s why I went for 2 x 8GB)

If you have more RAM, macOS will use more, even if it doesn't need it. Your current RAM usage might even be 15GB if you had 40 in the machine. macOS has the mentality that free memory is wasted memory, because even if you don't need the memory actively right now, it can put things in memory you might need later so it's already there. In Activity Monitor there's a graph for memory pressure. Use that to judge.

 

[Steve121178]

Learn how memory usage works, and no, don't waste more money on RAM you don't need.

 

[DeltaMac]

Are you expecting that adding memory will simply leave the extra memory unused?

Your Mac will try to use whatever RAM you decide to install.
macOS is pretty good about managing memory, and can release memory that is no longer in use, when other processes demand more memory.
Try not to micro-manage your Mac.
What SHOULD you do? Watch your Activity Monitor occasionally. Keep track of the normal condition of the Memory Pressure graph. If you note that the graph goes into the yellow, or even the red area occasionally, that can be your clue that you should consider adding more RAM (if possible). But, low in green area, and almost never higher, ignore your plans about adding RAM, and just use your Mac. It's working very nicely, thank you...

 

[Fishrrman]

Unless you are doing heavy video editing, you'll probably never "use 24gb up."

I think most folks will be "set for the future" with 16gb, and no more.

 

[macduke]

Oh I have more context now to better answer your question. Nah, you don't need more RAM. The system will release RAM when it needs to, and it will also compress RAM when it's getting low. I've been getting by on my work MBP that only has 16GB and I do way more complex stuff than you. Of course it's not ideal, but I'm crossing my fingers that iMac Pro is approved.