Which would be faster: my current fusion drive or a new external SSD?

[jcjost]

I currently have a late 2012 iMac with a 1TB fusion drive, which includes a 120GB internal SSD. Would performance markedly improve if I ran the iMac off of a new 1TB external SSD (such as the Samsung T5 or T7) instead of the fusion drive and just use the fusion drive for storage or backup?

Thanks,
John

 

[velocityg4]

Generally it should feel faster. Although depending on how much space you need for your OS and Apps. You could always split the Fusion drive up into a standalone SSD and HDD. Putting your OS and apps on the SSD while storing files on the HDD.

 

[bsamcash]

That model only has USB 3 and Thunderbolt 1. So, in theory, the internal IO should be much faster.

 

[smirk]

Keep in mind that if you connect the drive via USB then TRIM functionality is lost. There seems to be some debate on here as to how important that actually is. Some say without TRIM the hard drive will slow way down over time, while others maintain they've gone without TRIM for years with no issues.

 

[ADGrant]

For a 2012 I think your best bet would be replacing it if performance is an issue. According to some on this forum there is a glut of cheap late model Intel iMacs on the market. Failing that you could get the internal drive replaced with an SSD.

Alternatively, I think your Mac support target display mode. You could just buy an M1 Mac mini and use the iMac as a display.

 

[Nguyen Duc Hieu]

I currently have a late 2012 iMac with a 1TB fusion drive, which includes a 120GB internal SSD. Would performance markedly improve if I ran the iMac off of a new 1TB external SSD (such as the Samsung T5 or T7) instead of the fusion drive and just use the fusion drive for storage or backup?

Thanks,
John

It would be faster if you can split the fusion drive, move all the apps to the SSD and all data to the HDD.
If that's too much jobs for you, then an external SSD is quite a convenient solution.

 

[Fishrrman]

When I see a question like the OP's, my first question is:

What is the speed of your fusion drive NOW ??

Download Blackmagic Speed Test (it's free), run it, and post the results here for all to see.

If your 2012 iMac has USB3 (I think that some do, but others don't), you can plug in a USB3 SSD and expect to see reads in the 420MBps range.

That's why I asked about your speeds as they are now -- how much of improvement would it be?

 

[neilw]

Make of this what you will.

I had a 2013" iMac with Fusion Drive, and was using a Samsung T5 as backup clone. I likewise wondered if the T5 was faster than the internal Fusion drive, so for a while I flipped the arrangement... booted from the T5 and used the Fusion Drive as my backup clone.

My subjective assessment was that the T5 was perhaps a bit faster and more consistent, but there was no huge difference in overall system responsiveness.

HOWEVER.

I did get occasional (once every several days) kernel panics while using the T5 as my primary drive. These always occurred while the machine was sleeping (I would see the KP when I tried to wake the machine up). I never bothered to try to figure out why; at that point I simply switched back to the Fusion Drive and the problem went away. And so ended my experiment.

 

[MacCheetah3]

I currently have a late 2012 iMac with a 1TB fusion drive, which includes a 120GB internal SSD. Would performance markedly improve if I ran the iMac off of a new 1TB external SSD (such as the Samsung T5 or T7) instead of the fusion drive and just use the fusion drive for storage or backup?

Thanks,
John

As a person who replaced a 2012 Mac mini within the last 30 days, I know your position very well. Over the years, I doubled the RAM (8GB to 16GB) and internal storage, adding a 480GB SSD to the factory 500GB HDD. Obviously, this isn’t a typical Fusion Drive, the ratio of higher and lower performance drive capacity is nearly equal. During the last few months I did switch to an external NVMe drive connected via USB 3.0.

What were the results?

Surprisingly, similar to this:

My subjective assessment was that the T5 was perhaps a bit faster and more consistent, but there was no huge difference in overall system responsiveness.

Benchmark wise, its even more jaw dropping as formatted APFS my Fusion Drive reportedly wrote at anywhere from ~5MB/s to 100MB/s and read at 100MB/s to 200MB/s while the external SSD averaged ~400MB/s write and read. My conclusion, only performing frequent, large file/folder transfers and the like might have exhibited a notable difference in performance.

For the final recommendation, I again second another poster’s suggestion:

For a 2012 I think your best bet would be replacing it if performance is an issue.

Upgrades, such as the one you’re considering, do add a few more years of acceptable use of your computer. However, ultimately, I’ve concluded the value isn’t there — I say this while normally having a several year gap between replacing devices with recent models. In total, I probably spent $500 on top of the initial cost for that mini. Again, I recently purchased an M1 mini — specs in sig -- slightly used for $850 and it is remarkably faster overall. With that said… There is one more thing… If you want to stretch value also make your next purchase a refurbished — I recommend directly from Apple — unit. For examples, I’ll probably be considering a replacement for this M1 mini in ~5 years and plan on buying a refurbished iPhone 13 in 2022 to replace my X.

The end got a little rambling.

 

[whitby]

I actually bought a kit from OWC (Macsales.com and upgraded the internal hard drive in one of my iMacs (a late 2015 machine with a 2 TB Fusion drive). I then made a fusion pair of the internal SSD (128GB) and the SATA 2 TB SSD I installed. Not strictly necessary, but I wanted to make use of the 128GB internal SSD. The results were much better than the original Fusion drive but they are certainly not spectacular when compared to a more modern SSD M2 NVMe drive (450 MB/s against 300 MB/s for the Fusion drive - you have to be careful measuring speed because the OS moves stuff around from the SSD to the other drive so a Fusion drive can measure faster than it really is). Anyway it is quite a technical task and requires some care (removing the display panel is especially tricky or, more accurately, getting it back is tricky) but I have done dozens of upgrades on Apple products so was happy to tackle this.

The point is that this is one way to preserve your 2012 iMac and will cost a lot less than buying a new machine. However a 2012 machine is now 9 years old it may be time to retire it and invest in another machine (OWC have plenty of refurbished machines and, no, I do not work or have any relationship to them, I am just a long time happy customer of theirs).

 

[Yebubbleman]

I currently have a late 2012 iMac with a 1TB fusion drive, which includes a 120GB internal SSD. Would performance markedly improve if I ran the iMac off of a new 1TB external SSD (such as the Samsung T5 or T7) instead of the fusion drive and just use the fusion drive for storage or backup?

Thanks,
John

If you're using USB 3, then I'd argue that it might be a toss-up, seeing as you're running at 1Gbps slower of a connection to the drive than the 6Gbps SATA III connections that both the internal SSD and internal HDD use on that particular iMac. If you were using a Thunderbolt 1 drive, however, then it's highly possible that it'd be faster because the drive being used would likely be 6Gbps SATA III internally. Incidentally, if you could find an NVMe to Thunderbolt 1/2 enclosure and a decent NVMe drive, that would absolutely be faster than your Fusion Drive.

 

[jcjost]

Thanks everyone for your reply. I'm not sure I understood all of the comments. I downloaded Blackmagic and tried to check the speeds, but they seemed to constantly fluctuate. I also I didn't know which stress level to use. Using the 1GB stress level, write was about 150 and read about 375.

The external SSD would most likely use the USB 3.0 port; I can't find a drive or enclosure that uses Thunderbolt 1 or 2.

Thanks, John

 

[Fishrrman]

USB3 SSD should give you reads in the 420 range.
That's not "a really big jump" upwards from 375, but you will probably get a better "consistency of operation" from the SSD.

Get a 1tb SSD and then use CarbonCopyCloner to clone the contents of the fusion drive to the SSD. CCC may offer to clone the recovery partition as well, YES, do that too.

Again, it runs "in demo mode" for 30 days, so it won't cost you anything additional to get the SSD set up this way.