Question about TB3 & Internal vs External SSDs

[F-Train]

On my late 2014 27” iMac with Retina 5K Display, apps (17GB) and system (30GB) take up about 47GB of the 500GB SSD, and I use the balance of 453GB as a workspace for my current project. At its most complex, the current project might be the creation of a 10-20 minute 4K video. I keep almost all data, except for data relating to my current project, on external drives.

I intend to keep the iMac, but I am considering the new Mac mini as a supplementary computer dedicated to photo and video work. One of the attractions is that I can much more easily move it between two seasonal residences that are thousands of miles apart.

I have been assuming that the Mac mini should also have an internal 500GB SSD, but I’m beginning to wonder whether that is correct.

Let’s assume that I connect one of the Mac mini’s Thunderbolt 3 ports to an external 500GB or 1TB SSD.

If I do that, will performance suffer significantly if I use the external drive as my workspace and reduce the size of the Mac mini’s internal SSD to 256GB or even 128GB?

From a straight cost perspective, this is quite attractive, but I’ll admit that I don’t know what the performance implications are.

Thanks for your thoughts.

 

[xylitol]

Maybe this will give you some insight:

http://barefeats.com/hard232.html

As for whether the differences are significant, here's some comparison:

http://barefeats.com/imac5k1.html

 

[F-Train]

Maybe this will give you some insight:

http://barefeats.com/hard232.html

As for whether the differences are significant, here's some comparison:

http://barefeats.com/imac5k1.html

Thanks for that.

I should have done a search. This 2017 discussion goes a long way toward addressing the question: https://forums.macrumors.com/threads/external-vs-internal-ssd-speed.2090138/