How Do I set up my external SSD to be my main drive and have the iMacs HDD be empty?

[MartinAppleGuy]

H there! I just bought an external HDD and I want to install Mac OS onto it, make it the primary boot drive (so I don't have to hold down and buttons when restarting) and then completely format my internal HDD on the iMac (to use as storage space). How do I do this?

Many thanks, first time SSD user and went with a 512GB SSD to go along with an intel 1TB HDD and an external 1TB HDD setup

 

[DanBig]

H there! I just bought an external HDD and I want to install Mac OS onto it, make it the primary boot drive (so I don't have to hold down and buttons when restarting) and then completely format my internal HDD on the iMac (to use as storage space). How do I do this?

Many thanks, first time SSD user and went with a 512GB SSD to go along with an intel 1TB HDD and an external 1TB HDD setup

Follow this How to set up and use an external Mac startup disk - Apple Support

Once you've got the OS installed you can then go into the Startup control panel to select it.

I don't think this is the most ideal config as you're limited to a slower drive (HDD) and the limits of the connection. If you haven't bought the external drive yet, why don't you get an external Thunderbolt SSD drive. To gain still more speed you could get a RAID 0 drive.

 

[DeltaMac]

I am confused
Is the SSD internal, or external?
external SSD, through either Thunderbolt, or USB 3, would be pretty fast (much faster than a spinning hard drive, internal OR external)

If you want to use the external 1TB HDD as boot - what would you be using the SSD for? IMHO, you would have (by far) best results using the SSD as a boot drive, the internal HDD for other files (could even be setup as a fusion drive with the SSD), and the other external HDD for extra storage.

 

[chabig]

H there! I just bought an external HDD and I want to install Mac OS onto it, make it the primary boot drive (so I don't have to hold down and buttons when restarting) and then completely format my internal HDD on the iMac (to use as storage space). How do I do this?

Many thanks, first time SSD user and went with a 512GB SSD to go along with an intel 1TB HDD and an external 1TB HDD setup

I agree with DeltaMac. You mention an Intel 1TB HDD, a 512GB SSD, and an internal HDD. In the thread title you mention the iMac's HDD. It's all a bit confusing.

That said, if the iMac has an SSD, you're a fool if you don't make that the boot drive and use the external HDD for data.

 

[Fravin]

external SSD, through either Thunderbolt, or USB 3, would be pretty fast (much faster than a spinning hard drive, internal OR external)

Are you shure?

An external SSD through USB 3 should bee faster? Did you think it could de faster than a Fusion?

 

[nambuccaheadsau]

Yes it will be fast. I did this some time ago with a 2011 iMac via Thunderbolt. Fusion is faster as the SSD portionis Flash Storage, PCI-E.

 

[DeltaMac]

And, if you use USB 3.0 with SSD, you want to make sure that the external enclosure supports UASP, so that the SSD works at full speed.

 

[MartinAppleGuy]

I am confused
Is the SSD internal, or external?
external SSD, through either Thunderbolt, or USB 3, would be pretty fast (much faster than a spinning hard drive, internal OR external)

If you want to use the external 1TB HDD as boot - what would you be using the SSD for? IMHO, you would have (by far) best results using the SSD as a boot drive, the internal HDD for other files (could even be setup as a fusion drive with the SSD), and the other external HDD for extra storage.

I want an external SSD (a USB 3 enclosure) to be the boot drive, and the internal HDD for basic files (so fully blank).
[doublepost=1489830114][/doublepost]

And, if you use USB 3.0 with SSD, you want to make sure that the external enclosure supports UASP, so that the SSD works at full speed.

I've got one that does so how do I go about getting Mac OS on the external SSD, making it my boot drive, and formatting the internal HDD?

 

[maflynn]

I just used Carbon Copy Cloner to copy the internal drive to the external SSD. I then booted up on the external drive. I then also set up the internal drive by breaking Fusion, and partitioned and formatted the spinning drive

If you don't have a Fusion drive, then just repartition the drive the way you want and/or reformat it.

 

[DeltaMac]

Yes, there's some simple steps that will do what you want.
As maflynn described - Clone your internal to the external SSD. CCC is designed to do exactly that.
When that completes, set the external drive as your boot drive, using the Startup Disk pref pane.
Boot to the SSD. Erase your internal using Disk Utility.
That's pretty much it.

 

[MartinAppleGuy]

Yes, there's some simple steps that will do what you want.
As maflynn described - Clone your internal to the external SSD. CCC is designed to do exactly that.
When that completes, set the external drive as your boot drive, using the Startup Disk pref pane.
Boot to the SSD. Erase your internal using Disk Utility.
That's pretty much it.

I want a fresh install on the SSD. So I guess I'll just press cmd R on bootup, install Mac OS on the external SSD, boot into it, set it as boot drive, and then format the Macintosh HD (internal HDD) in disk utility?
[doublepost=1489841865][/doublepost]

Yes, there's some simple steps that will do what you want.
As maflynn described - Clone your internal to the external SSD. CCC is designed to do exactly that.
When that completes, set the external drive as your boot drive, using the Startup Disk pref pane.
Boot to the SSD. Erase your internal using Disk Utility.
That's pretty much it.

I guess I format my SSD before anything tho eh? GUID partition map and Mac OS journaled correct?

 

[ZipZap]

An external SSD is not going to outperform any internal drive.

 

[MartinAppleGuy]

An external SSD is not going to outperform any internal drive.

Weird how my SSD is getting 5-6X the read write speeds of my internal HDD lol

 

[Fishrrman]

OP:
Here's how to do what you want:
https://forums.macrumors.com/threads/how-to-set-up-an-external-ssd.2037288/#post-24402360

 

[DeltaMac]

An external SSD is not going to outperform any internal drive.

That's not correct. An external SSD (particularly when the enclosure supports UASP) using a USB 3.0 connection, will absolutely be faster than any internal spinning HDD.
It may not be faster than that same drive installed internally - but is a good solution when installing your own SSD is impractical (or outside of your tech skills)

 

[nambuccaheadsau]

Like treacle and lightning over a slow 7200 rpm drive. The day of the platter drive is gone!

 

[MartinAppleGuy]

Like treacle and lightning over a slow 7200 rpm drive. The day of the platter drive is gone!

All up and working and its silly fast compared to my internal HDD. iTunes opens after a boot in less than a second, and before it would have been 7 seconds.

 

[ljonesj]

Not for mass storage for now as 2tb ssd are still very expensive compared to a 2tb hd 800$ vs 120$ max