Downside of a DIY Fusion Drive

October 28, 2013 at 10:25 pm Leave a comment

This is a long-winded post, so skip it unless you are really interested in DIY Fusion drives and the strange issues I’ve started having.

Almost 1 year ago, I posted about creating my very own DIY Fusion drive.  I combined a Crucial M4 128GB SSD with a 500 GB HDD in my Mac Mini.  It has had it’s ups and downs.

My first BIG problem

Much earlier this year (I don’t believe I posted about it at the time), I had an issue with my Fusion drive.  All of a sudden, it stopped working.  From what I could gather, the SSD died.  After much experimentation, and after I had wiped the 500 GB hard drive, the SSD suddenly came “alive” again.  I think I upgraded the firmware at this point, did a bit of testing, and all seemed well.  Ultimately, I restored my time machine backup to an external drive, then cloned it to my Fusion drive, and was back in business.

Since around this time, I have occasionally had odd issues involving a noise emanating from my Mini.  Usually, this happens just a few times (sometimes, just once) then it goes away.

UH OH!  It’s getting worse!

Fast forward to the last month.  This problem started happening, and overstayed its welcome.  I’m talking for 20+ minutes of odd beeps coming from my mac.  I’ve tried powering it down and letting it cool off, among other things.  None of that worked.  Finally, I loaded SMART Utility to see if there were any errors, but there were none.  This problem continued, every few minutes (or more often), even after reboots.  Leaving it powered off for an hour or so didn’t seem to help.

Then I discovered something strange.  In the SMART Utility, I kicked off a “Long” test on the hard drive, and the noise seemed to go away.  This test takes a few hours to complete, but after the test was over, the noises stayed gone for the rest of the day.  Perhaps it was several days.  I thought it was a coincidence, and didn’t think too much of it.  Some days or weeks later, the problem returned.  Again, I tried powering it down, letting it cool off, etc. but the issue kept coming back.  Then, I tried the SMART test again and again it disappeared.

Aside from the beeping, this past weekend I started to hear a clicking noise.  This was at its worst on boot-up a few days ago, when my machine wouldn’t successfully boot at all.  I powered it off, gave it a little rest, then powered it back up.  It started up, and soon started with the clicking noise again for about 10 seconds or so, then that stopped and the machine booted normally.  This REALLY makes me think the problem is the hard drive.  Side Note: I’m doing VERY regular backups at this point.

Anyhow, when I first started using the SMART Utility, I noticed something odd.  The “Power On Hours” was in the 300 range for the SSD, but over 18000 for the hard drive.  18K hours works out to just over 2 years.  I’ve had this machine for a little shy of 2 1/2 years, having bought it right after it was released (a mid-2011 Mac Mini).  So, the SSD is sleeping when not needed, but it doesn’t appear that the hard drive was, even though the power management settings on my Mac instruct it to put the drives to sleep when possible, though I have to admit that I’ve only been running a Fusion drive for just over a year.  I’m guessing I didn’t always have this sleep setting at this value, but I don’t know when I enabled it.  If it were recent, I’d probably remember doing it though.

In doing more checks, I found that Trim Enabler is showing that Trim isn’t enabled now.  This was probably broken when I updated to some newer version of Mac OS X.  This makes me wonder if Trim Enabler with a Fusion drive causes problems with Mac OS putting the fused hard drive to sleep.  Or perhaps that is just a problem of a DIY Fusion drive.

While I don’t have concrete answered on this, my bottom line is this:  Fusion drives are prone to failure, more so than either a SSD or a HDD.  If either the SSD or the HDD flakes out, your data is toast!  While it does offer performance over and above a lone HDD, and it is so inexpensive to add it yourself, it doesn’t seem to be well supported with aftermarket SSD’s.


I’m giving up on Fusion drives.  Having good performance for a low price sounded great, but dealing with an issue that sometimes LITERALLY keeps me up at night (or wakes me up), well, it’s just too much.  Yes, SSDs are expensive, but my time is more valuable than to be troubleshooting these sorts of issues at all hours of the night.

I’ve ordered a Samsung 840 EVO drive of sufficient enough of a size that I’ll no longer need the HDD.  I expect it to arrive soon and plan to post about my results.


Entry filed under: General, Mac.

My experience with New Samsung 840 EVO SSD install in 2011 Mac Mini

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

Trackback this post  |  Subscribe to the comments via RSS Feed


October 2013
« Sep   Nov »

Most Recent Posts

%d bloggers like this: