2017 5K RAM Upgrade: Not Faster (After Effects) ?

[Samurai Shampoo]

Hi guys.

I upgraded my 2017 5K iMac (3,5GHz i5 CPU) with two 16GB Crucial RAM sticks (they are compatible with my iMac model).

I now have a total of 40GB RAM (2x4, 2x16).

Order in the RAM slots: 4, 16, 4, 16

I did the start up diagnostics test and it came back as OK.
System report shows all sticks are OK.


Now, I use After Effects 2020 and I'm confused as to why I see no speed gain and AE takes up all RAM even when I do really simple tasks in AE, like 2 static solids, 2 texts and a video.

When I preview my composition the playback is choppy frame by frame just as it was when I only had 8GB of RAM.
AE hogs 36GB of RAM after playing 20 seconds of the video.

Maybe the CPU is too weak?
Current Cinebench R20 scores for my i5 CPU = 1592 pts, CPU (Single Core) = 426, MP Ratio = 3,74x


Does anyone know why I see no improvement in AE or why AE hogs all of my RAM despite not really needing it?

Any AE users here?

 

[posguy99]

Does anyone know why I see no improvement in AE or why AE hogs all of my RAM despite not really needing it?

Because you weren't RAM-bound before. As for an application taking more RAM, why did you install it if you did not expect it to be used for something? Cache, if nothing else.

 

[chabig]

A larger gas tank doesn’t make a car faster. Likewise, you should not expect RAM to make a computer faster. There are edge cases when too little RAM will become a bottleneck and slow the computer. But that’s rare.

My guess is that your machine has a spinning hard drive. Replace that with an SSD and you will see a difference.

 

[Samurai Shampoo]

Because you weren't RAM-bound before. As for an application taking more RAM, why did you install it if you did not expect it to be used for something? Cache, if nothing else.

I need RAM for better playback. With 8GB of RAM I had to work at Quarter Resolution and animate basically without seeing smooth previews at all.

A larger gas tank doesn’t make a car faster. Likewise, you should not expect RAM to make a computer faster. There are edge cases when too little RAM will become a bottleneck and slow the computer. But that’s rare.

My guess is that your machine has a spinning hard drive. Replace that with an SSD and you will see a difference.

I have a SSD.

 

[Fishrrman]

This is video we're talking about?
If so, is it 1080p or 4k...?

 

[chabig]

I have a SSD.

Then disregard that comment. The first part of my comment contains your answer.

 

[IowaLynn]

I wonder if a synthetic benchmark with just the Crucial 32GB would show a difference. Synthetic, not real world. Might. All same latency and higher density. SSD: larger does have more I/O channels and are faster.

 

[Fravin]

AE previews are related to GPU processing power. Not RAM.
Actually Macs have top tier RAM management. It won’t be a concern for almost everyone.
But GPU should be your problem.

 

[jz0309]

I don't know AE, but, before you got the add RAM, did you check your memory pressure in Activity Monitor? and now, with adds RAM?
Clearly there are apps that will use more RAM but I would always check RAM usage before just buying RAM

 

[alien3dx]

For me developer, I had basic iMac 2017 and 8 GB ram.To super optimize my compiling I used ram disk as my cache.So maybe anybody here have used ram drive as a scratch drive for optimization cache.