SOLVED Boot from SSD but run most applications from external HDD?

[AutoMac]

Currently I have a 21.5” iMac running the Big Sur OS and all applications from a fast external 2TB HDD (bigger and faster than the internal HDD which is unused).

I plan to replace it with a 27” iMac which will have a 256GB SSD with Big Sur and am thinking of also loading ‘graphically heavy and performance-demanding’ applications like Lightroom and Photoshop on the SSD but run all other ‘lighter’ applications and all user files from my existing external HDD.

The boot drive is the SSD and the HDD is the data drive (and most applications) and still has a copy on Big Sur (in case I need to boot off it one day).

Does this sound like a sensible plan? Are there any difficulties in ‘calling’ applications or data to run from a different drive (other than a performance difference)? Thanks in advance for any help.

 

[Nukeban]

For what it's worth, I've been booting and running applications from an external drive connected by Firewire for years. Just in the last week the external drive died, and so I'm temporarily running off the ten year old internal drive. Technically I suppose there is a speed difference between booting and running off the external via the internal, but I rarely notice it.

I'm on a ten year old 27inch iMac I bought used a few years ago for $900. It has 16GB ram and a 1TB internal drive (not ssd) I do tons of video work in Hitfilm, pretty much every day for the last few years. I can't really run the latest versions of Hitfilm, but an old version runs fine and does everything I need. I'm also able to run a recent version of Poser without difficulty. All of the above typically run off the external drive.

I don't boot from one drive and run apps from another drive, so can't comment there.

 

[AutoMac]

For what it's worth, I've been booting and running applications from an external drive connected by Firewire for years. Just in the last week the external drive died, and so I'm temporarily running off the ten year old internal drive. Technically I suppose there is a speed difference between booting and running off the external via the internal, but I rarely notice it.

I'm on a ten year old 27inch iMac I bought used a few years ago for $900. It has 16GB ram and a 1TB internal drive (not ssd) I do tons of video work in Hitfilm, pretty much every day for the last few years. I can't really run the latest versions of Hitfilm, but an old version runs fine and does everything I need. I'm also able to run a recent version of Poser without difficulty. All of the above typically run off the external drive.

I don't boot from one drive and run apps from another drive, so can't comment there.

Thanks Nukeban, very helpful! Interesting that you run all that on 16GB RAM. My change of machine is ‘forced’ by needing more than my present 8GB of RAM (not user changeable) as Lightroom needs a recommended minimum of 12GB and I have just been scraping by for several years with loads of lag. I was thinking to go to 32GB but maybe that is just excessive and would give no real benefit beyond your 16GB.

 

[Nukeban]

Thanks Nukeban, very helpful! Interesting that you run all that on 16GB RAM. My change of machine is ‘forced’ by needing more than my present 8GB of RAM (not user changeable) as Lightroom needs a recommended minimum of 12GB and I have just been scraping by for several years with loads of lag. I was thinking to go to 32GB but maybe that is just excessive and would give no real benefit beyond your 16GB.

Yea, 8GB of Ram is ok for web surfing and email (most people's usage) but it's not really enough for video work. My suggestion would be to get as much RAM as you can afford. 32GB sounds good, but I don't recall the price.

Again, my set up works because I'm running an old version of HItfilm 4 Express for video work. I think they are on version 15 or something these days. So I'm way behind the cutting edge. This works for me, but could be frustrating for many others.

For graphics, I make occasional use of Graphic Converter and Gimp. Both seem happy on my setup, though I'm probably using old versions there as well.

The best test may be Poser, as 3D apps are typically very demanding. I've had various experts tell me to just forget about 3D on a Mac, any Mac, but Poser seems pretty happy here, and in that case I'm only one version behind the latest.

There are other limitations to my old machine however. As example, my Firewire drive just died and when I went to purchase another on Amazon I see that few companies are still selling Firewire drives because this connection system has been abandoned for some time now.

Big Sur may be an issue for you, but I don't know anything about it. Just now reading some stuff about issues booting from external drives. If you haven't already you might want to look in to that. Ideally you would find users doing what you want to do on the machines you want to buy.

 

[Cory Cooper]

Hello,

Many applications require them to reside in the Applications folder on the startup drive, as their update mechanism looks for them there. In addition, they install other support pieces in various places like the Library and User Library folders.

With the built-in 256 GB SSD, most people can install all of their applications on this OS/startup drive. You can store your files/data on external Thunderbolt drives, and run them from there without a noticeable speed difference, especially if it is an SSD Thunderbolt drive.

NOTE: If you are looking at the new 24" M1 iMac, it has a limit of 16 GB RAM, which is not user-expandable.

Hope that helps.

C

 

[AutoMac]

Hello,

Many applications require them to reside in the Applications folder on the startup drive, as their update mechanism looks for them there. In addition, they install other support pieces in various places like the Library and User Library folders.

With the built-in 256 GB SSD, most people can install all of their applications on this OS/startup drive. You can store your files/data on external Thunderbolt drives, and run them from there without a noticeable speed difference, especially if it is an SSD Thunderbolt drive.

NOTE: If you are looking at the new 24" M1 iMac, it has a limit of 16 GB RAM, which is not user-expandable.

Hope that helps.

C

Thanks Cory, that's useful info. I see that the spec of the SSD that I intend to get is 512GB, so I will do my math to see what apps will sensibly fit into that space and, if necessary, prioritize which goes on the SSD.

My external drive (by choice) is a 2TB 'hybrid' Seagate Firecuda drive - a good mix of speed and economy - as I couldn't justify (or really need) running to a 2TB SSD...

Re my choice of Mac - no, I am looking to get a new 2020 iMac to ensure that I can change the RAM. I don't really understand why Apple need to go to the 'soldered-in' RAM solution which makes the kit much less user-friendly.

Thanks for your helpful reply.

 

[AutoMac]

Yea, 8GB of Ram is ok for web surfing and email (most people's usage) but it's not really enough for video work. My suggestion would be to get as much RAM as you can afford. 32GB sounds good, but I don't recall the price.

Again, my set up works because I'm running an old version of HItfilm 4 Express for video work. I think they are on version 15 or something these days. So I'm way behind the cutting edge. This works for me, but could be frustrating for many others.

For graphics, I make occasional use of Graphic Converter and Gimp. Both seem happy on my setup, though I'm probably using old versions there as well.

The best test may be Poser, as 3D apps are typically very demanding. I've had various experts tell me to just forget about 3D on a Mac, any Mac, but Poser seems pretty happy here, and in that case I'm only one version behind the latest.

There are other limitations to my old machine however. As example, my Firewire drive just died and when I went to purchase another on Amazon I see that few companies are still selling Firewire drives because this connection system has been abandoned for some time now.

Big Sur may be an issue for you, but I don't know anything about it. Just now reading some stuff about issues booting from external drives. If you haven't already you might want to look in to that. Ideally you would find users doing what you want to do on the machines you want to buy.

 

[AutoMac]

That’s very helpful again Nukeban. In UK the 32GB RAM from Crucial will be about GB£145 (double the 16GB) - at around US$200 - which is minimal alongside the iMac cost, and is also a ‘one off’ cost so I shall take your advice!

I now recognise that I chose badly in getting the original iMac with 8GB RAM - I think I was in $-shock as I was forced to immediately replace a ‘dead’ MacBook Pro at an unwelcome moment...

Happily both Lightroom and Photoshop will be my most demanding applications - way less than Poser. Many thanks again.