Use Fusion drive for everything or not?

Fusion Drive is made for this

Your 3TB fusion drive is made for this! Just put all your data on it .
The System will decide what it puts where for optimal speed.
So no external disk needed for your data.
Use an external disk for time machine Backups. It should be about 1.5-2 times bigger than the total space you use on you Fusion drive.
A good size would be 3-4TB.

 

This is what I do. Put everything on the Fusion but make sure you back the thing up frequently.

 

+1

I'm not sure why you said you should configure the Fusion Drive. Since the Fusion Drive is part SSD, and the OS is aware of it, the OS decides which files to move to the SSD, and it does this automatically. It will move the most frequently accessed files to the SSD for you. So just stick everything onto the Fusion volume and you never have to think of it. For really large files that you rarely access, go with the external drive if your main volume is full. I have big movie rips and they go onto my external drive/NAS and I also back up using timemachine to an external 3TB drive.

 

What do you guys plan on doing if you power your iMac on tomorrow and find that it has died?

Do you risk sending your iMac in to Apple for repair, and trust (hope?) they don't look at your confidential data - bank statements etc. And trust (hope?) that they completely and thoroughly wipe the internal drives if the are removed and replaced?

I would not be at all comfortable with that.

Or do you plan on dismantling your iMac and removing the drives before returning it? And arguing with Apple who tell you they aren't repairing it because you have invalidated the warranty.

For these reasons, I will be putting my personal data on an external drive and only putting apps and public domain stuff on the internal drive.

 

Encrypt the drive with FV2. If the drive is replaced... the data is encrypted and unusable.

Set up (in advance) a sterile, non-administrator login to be used for repair.

/Jim

 

+1
I had the scenario just a few weeks ago. Apple replaced my 1TB disk as preventive maintenance.
I just wiped my data directories before I turned the iMac in.

In case I cant' boot rom the internal disk I have an external FW800 boot drive clone (CCC).
And I have a "clean" administrator account (can give apple the password for troubleshooting).

For sensitive data I use an encrypted disk image. (http://support.apple.com/kb/HT1578?viewlocale=en_US&locale=en_US)

 

The encrypted volume is of course fine for super sensitive stuff like banking passwords and bank statements and scans of your passport or driving license that you had to send to whoever.

Actually, I say it's fine, but actually it isn't. SSD's - because of how they do wear levelling and background garbage collection - are not secure devices. They leave copies of data hidden on the drive when they do their internal housekeeping and it is impossible to wipe this without doing a secure erase of the whole drive, which you can't do if the machine won't power up. So what about those files that you moved to the encrypted volume? Some are still visible on the SSD if someone really wanted to try.

And what about your photos? Or the letter you wrote to BMW complaining about their service? Or the video of your 3year old in her pyjamas opening her Christmas presents?

I am not sure i want any of that in the hands of complete strangers.

Ok, so you could encrypt the whole drive, but what does that do to performance?

On balance, I think it's just a whole load easier to install only a small SSD in your iMac and put everything else on an external drive. If I had a Mac with an internal fusion drive, personally I would unpair the SSD and hard disk and just use the SSD for the OS and apps.

Just my personal preference.

 

In my experience... it is negligible. One of the very first things that I do with a new computer is turn on FV2.

/Jim

 

From Wikipedia

The performance penalty for using Filevault 2 was found the be in the order of 20 – 30% when using CPUs with the AES instruction set, such as the Intel Core i.[13][14

 

That percentage seems rather high, with the exception of startup time.
For actual use I notice no performance difference at all. benchmark wise on my Crucial M4 I only see a drop of a couple of MB/s which is negligible.

A few months ago I switched from using a 512GB SSD and 1TB HDD in my MBP as separate drives over to a Fusion setup. It's worked very well so far and so much easier than manually shuffling files around.

As for backups incase of failure, I use Time Machine and if I had to return a broken drive I have FV2 enabled so no worries there.

 

Everyone must do what they feel works best for them of course, and there's no denying the superficial appeal of what appears to be a single drive that does everything.

But I have run an SSD and seperate hard disk for years and that's what works best for me. I don't recognise the "manually shuffling files around" overhead. I put the OS, programs and temporary data on the SSD; everything else on the hard disk. It boots like the wind, programs launch instantly and everything is as fast as you could wish (given the limitations of my modest 2.3GHz dual core i5!)

I hardly every need to move files from one drive to the other, and if I do it's so trivial an exercise as to be irrelevant. If that is a problem, you might as well say don't use Finder at all.

 

the external drive it is a hdd or ssd too, so even this can be replaced or repair? so it is the same case

 

No. If it breaks, you take the drive out and smash it with a hammer and throw it away.

Would you do that to your iMac?

So, no, it is not the same case.

 

Another vote in favour of keeping the Fusion drive. There's nothing superficial about it.
It is the best of both worlds: speed of SSD with capacity of HDD; and it is more efficient at moving the data between the two than you will ever be.

 

I have everything on my 1tb Fusion. Then I back up to a 1tb external using Time Machine plus use Carbonite. No problems for me to report.