RAM upgrade for an iMac 27" 2017 used for video-editing, compression and audio recording I have a 27" iMac (2017) - 4.2 GHz Intel Core i7 - Radeon Pro 580 8 GB - 16GB DDR4 running macOS Mojave 10.14.6.

I do a lot of video editing, compression and record a lot of Live DJ Sets with a Pro DJ Suite.

At this point, the video editing and compression is going 'ok', but if it could be a little bit faster, I would not mind.

In light of this work, would upgrading the memory from 16GB to 32GB be useful?

In other words, if I add an extra 16GB to the system, will I have better results* when working on video files? 

*Better results = faster completion.
I'm a big believer in having more RAM generally, but of course in many situations having more RAM isn't warranted. In your case, however, having more RAM is going to be useful because of the type of tasks you're using your iMac for. 

The key spec missing from your question, however, is the type of storage you have. If your iMac has one of the Fusion drives, then you'll get more out of your extra RAM than you will if you have an internal SSD. This is because macOS will use your storage device for virtual memory when it doesn't have enough RAM available.

In summary, if your internal drive:


is a Hybrid/Fusion drive, then definitely upgrade your RAM.
is an SSD, then strongly consider upgrading your RAM