Awsomesauce

got it thank you to you both  for all the great input Much appreciated

Oh and the RAM too - I changed it out and misordered and ended up with 24 not 32.  but hopefully its OK for now.  I didnt know its better for it all to be the same speed and type.  I'll make a note so much to know and learn!  Again thank you

all good info thanks so much I only updated to Mojave recently and did have the 16 bit challenge before that.... so Im not sure its that.      I think because I was compositing with many many many layers and trying to do it all in 16 bit that was the issue.  Just the huge size of every little bit.    I guess I was trying to understand what I would need to change out in my mac to be able to do that if I ever needed to again....?  I can also change my process - flattening along the way but that is not the way I like to work.  I like Damiens idea of just turning it to 16 bit before delivery.  Its likely it won't come up often though thank goodness.

I really appreciate the backup comments - I had no clue what I was doing and was aiming for 2 backups of everythying.....somewhere!  I just signed up for an online backup service too so now I could definitely set up one of them - the ex drives -  (the smaller one?) as a backup and keep my other one for my files.  Is there a way of sorting out what is on one drive (files wise not backup wise) and getting it copied over to the other drive without doing it manually pls?

Not trying to be difficult here trying to understand - if I open something, drag it and drop it and close it?  It seems to be the main file size I think that causes me problems.  For example if I have lots of layers and then I want to move something - move a layer or transform it for example - it either doesn't move for a very long time (so I can't control it) or it moves very very very slowly........or the whole thing locks up........or PS crashes - those were the kinds of things I was experiencing.........With just the huge 16 bit many layers file open - nothing else at the same time.  And yes I must remember to file place.

Yes I am guilty of cutting out in ps and then dragging and dropping from one file to another in ps - always forget the file place bit. Or I open the file in PS and then drag n drop it.  How does that not help here?

??? - sounds like a plan - can a PSD be converted into 16 bit?  All the layers?

oh yes ! 

I know and I usually work in 8 bit .  It was a photo compositing project and I managed to get it done but Im wanting to to figure out the issue so if it comes up again I can solve it

No - I didnt ask    I just couldn't figure out why working in 16 bit caused me slowing and crash issues.

I was asked to for a project I was working on. 

no they are not - I edit them from an external and save them there....I thought that a better route?

HI Damien - thank you.  I have two external drives for my photo work and my internal hard drive .  I restart every day

Hello Brian and all - Ive had an issue for some while and have done all kinds of research but not found a solution and not being technically minded am not sure what to look at next.  Basically, working in 16 bit with lots of layers  slows Photoshop CC considerably and eventually crashes it.  Im looking for a solution..... I'll attach some system info.  Thank you

Thanks so much I'll try it?

Hello there......I finally got all my photos off my internal hd and onto an external drive.   I upload new pics to the external and work on them from there also.  My goal is to have a backup.   I have another external drive.  I would like to know how to automate the backing up of the photos file from one ext hd to the other.   Thank you.