SSD Vs Fusion Drive iMac

[aevan]

And the best part about external storage is that if you have more than one Mac (most people I know do), you can access your data from any Mac you want. Just stick in the external and off you go.

You guys act as if HDDs fail left and right. I have HDDs that are 7 years old and still running. Again - yes, SSDs are more reliable, but you are actually expecting HDDs to fail? Do you expect everything mechanical to fail? You do know the fans in your computer are also mechanical and internal?

Yes, SSDs are generally more reliable. But that doesn't mean HDDs just fail by themselves. I've had computers for 20 years now, I've only had one HDD malfunction during all that time.

 

[yjchua95]

You guys act as if HDDs fail left and right. I have HDDs that are 7 years old and still running. Again - yes, SSDs are more reliable, but you are actually expecting HDDs to fail? Do you expect everything mechanical to fail? You do know the fans in your computer are also mechanical and internal?

Yes, SSDs are generally more reliable. But that doesn't mean HDDs just fail by themselves. I've had computers for 20 years now, I've only had one HDD malfunction during all that time.

Were any of your drives made by Seagate?

 

[AppleFan360]

You guys act as if HDDs fail left and right. I have HDDs that are 7 years old and still running. Again - yes, SSDs are more reliable, but you are actually expecting HDDs to fail? Do you expect everything mechanical to fail? You do know the fans in your computer are also mechanical and internal?

Yes, SSDs are generally more reliable. But that doesn't mean HDDs just fail by themselves. I've had computers for 20 years now, I've only had one HDD malfunction during all that time.

Your comments are falling on deaf ears. The SSD evangelists around here swear up and own by them and nothing you say will change their minds. Like you, I think I have had only one hard drive fail in the 30 years I've been using them. Sure, they are slower than SSD's but they do the job they are designed to do. Slow or fast, that's all that really matters.

 

[Sirmausalot]

I am referring to high resolution (1080p at least or 4K) video. Of course an HDD works, but if you have a large budget, an SSD RAID 0 array will reduce the processing time...

Let's not forget you should never put video on a system drive anyway. And this discussion is about system drives!

 

[Alesc]

Were any of your drives made by Seagate?

The 750GB Seagate in my mid-2007 iMac is still spinning 8 years after...
And SSD wears and fails too... Even with TRIM enabled. They are technical devices, not magical artefacts.

http://www.enterprisestorageforum.c...sd-vs.-hdd-performance-and-reliability-1.html
http://www.computerworld.com/articl...o-die--as-linus-torvalds-just-discovered.html
http://www.tomshardware.com/reviews/ssd-reliability-failure-rate,2923.html

 

[yjchua95]

The 750GB Seagate in my mid-2007 iMac is still spinning 8 years after...
And SSD wears and fails too... Even with TRIM enabled. They are technical devices, not magical artefacts.

http://www.enterprisestorageforum.c...sd-vs.-hdd-performance-and-reliability-1.html
http://www.computerworld.com/articl...o-die--as-linus-torvalds-just-discovered.html
http://www.tomshardware.com/reviews/ssd-reliability-failure-rate,2923.html

And good MLC drives last way longer than the lifespan of your computer...

http://techreport.com/review/27436/the-ssd-endurance-experiment-two-freaking-petabytes

2 PB of writes and still counting.

 

[redheeler]

You guys act as if HDDs fail left and right. I have HDDs that are 7 years old and still running. Again - yes, SSDs are more reliable, but you are actually expecting HDDs to fail? Do you expect everything mechanical to fail? You do know the fans in your computer are also mechanical and internal?

Yes, SSDs are generally more reliable. But that doesn't mean HDDs just fail by themselves. I've had computers for 20 years now, I've only had one HDD malfunction during all that time.

As I said HDDs can last a long time, as in the case of my original iMac. But they can also fail pretty quickly, especially if used heavily, and on average will fail well before an SSD does.

Were any of your drives made by Seagate?

I'm amazed the stock Seagate HDD in my 27" 2010 iMac still works considering how loud that thing is and there was even a recall program for it. One thing's for sure, that machine could really benefit from an SSD.

 

[henriquede81]

#1: Fair enough. But you're probably not buying a new iMac if you have "limited money resources"

#2 Spoken like someone who regrets buying the Fusion Drive. I'm sorry young fella, but you're wrong. Every aspect of using the computer is faster on the pure SSD drive Macs. EVERY ASPECT. Anyone who owns both can tell you this.

#3 You keep believing that. It's good to have dreams. Also, nobody 'upgrades' internal hard drives on an iMac — with the exception of people who realize they got suckered into saving money on a Fusion Drive and finally want to replace it with pure SSD.

#4 See response to #3. Beyond that, very few consumers upgrade anything in an iMac — because most consumers know absolutely nothing about how a computer works.

Remind what I've told: "SMART choice" ... so if I talk about limited resources doesn't mean that I'm a poor guy, even a poor guy deserves the best choice ... maybe I'm just smarter than you MacGizmo because I care about where my investment goes.

Because I can compare, I can check the daily performance of a one year old iMac pureSSD against a retina one brand new with Fusion Drive. I swear to you MacGizmo, I cannot say which one is the fastest for a “normal daily usage”! I’m sorry for that.

I'm also sorry to disappoint you but I actually upgrade almost all PCs and Macs I own. RAM, HDDs, SSDs but also a couple CPUs were kind of "piece of cake" a few months later once the prices went down or the warranty was no longer existing. I’m doing this since ever! Am I the only one?

I'm glad to hear from you, young fella.
Cheers

 

[marzer]

As I said HDDs can last a long time, as in the case of my original iMac. But they can also fail pretty quickly, especially if used heavily, and on average will fail well before an SSD does.

It would help if some statistical data was presented to support such statements. In the case of SSDs, they are still relatively new. Most early generations are just hitting EOL expectations, at least from data cycle standpoint. IDE type HHD have been around for 25+ years.

In my experience, over the past 25 years, I've owned maybe 40 hard drives (internals, externals, NAS, etc), some operating 24/7. Failure has been very rare, I can estimate approximately 1 in 10 failing on me. And none of those were pretty-quick failures, but drives that had been in use for some notable period of time.

I started using SSD about 3 years ago. In that time I've owned about 6 and 1 (a Crucial) already failed on me. I'd suggest the historical evidence needs to be given time to accumulate yet regarding SSD long term reliability.

 

[joema2]

...I started using SSD about 3 years ago. In that time I've owned about 6 and 1 (a Crucial) already failed on me. I'd suggest the historical evidence needs to be given time to accumulate yet regarding SSD long term reliability.

SSD first became an iMac option in 2010. It would be interesting to see what the reliability has been over five years for those units.

It is common sense that as a class SSD is more reliable than HDD. I wonder if that's true on a size-adjusted basis? IOW if the SSD capacity was scaled upward to equal the HDD size it's being compared to, that would include a lot more storage cells which could fail.

We do know that SSDs can have very substantial failure rates. SSD reliability can vary a lot, just as HDD reliability can vary a lot.

http://www.rockpapershotgun.com/2014/01/30/are-ssds-reliable/v
http://www.extremetech.com/computin...might-be-the-only-reliable-drive-manufacturer
http://www.extremetech.com/computin...ing-drive-are-power-outages-killing-your-ssds
http://www.tomshardware.com/reviews/ssd-reliability-failure-rate,2923.html

 

[sugawi]

I went with SSD. Fusion drive would escalate potential failure rate x2 since there's 2 devices that can fail vs 1. Extra storage can be used externally if needed but 1TB SSD should be enough for my needs. I had fusion before and got tired watching beach ball while working on large video files.

 

[joema2]

...1TB SSD should be enough for my needs. I had fusion before and got tired watching beach ball while working on large video files.

Just curious, are those large video files all on your SSD or stored externally? On the FD were they likewise stored externally?

 

[sugawi]

Just curious, are those large video files all on your SSD or stored externally? On the FD were they likewise stored externally?

All files stored internally, used about 400gb of space.

 

[joema2]

All files stored internally, used about 400gb of space.

Since you were doing heavy-duty video editing with video files, library files, scratch files, etc. on the same Fusion Drive as your operating system, that could definitely explain why it seemed slow. Yes in that case SSD might be a better choice -- provided all that continues to fit.

 

[Alesc]

I went with SSD. Fusion drive would escalate potential failure rate x2 since there's 2 devices that can fail vs 1. Extra storage can be used externally if needed but 1TB SSD should be enough for my needs. I had fusion before and got tired watching beach ball while working on large video files.

The failure rate is not x2 in a Fusion Drive... I can't find the calculation anymore, but the FD reliability equals the one of the less reliable drive.

 

[sugawi]

The failure rate is not x2 in a Fusion Drive... I can't find the calculation anymore, but the FD reliability equals the one of the less reliable drive.

What I meant that it has 2 parts so failure potential would be present for each drive which something I do not want to gamble with.

 

[joema2]

What I meant that it has 2 parts so failure potential would be present for each drive which something I do not want to gamble with.

Both SSD and FD have *many* parts which can fail. They both contain many chips -- microcontrollers, RAM, capacitors, PCB, etc.

So it's not like one part that can fail vs two parts -- it's like 98 parts vs 99 parts.

This helps explain why historically SSDs have had substantial failure rates, although generally less than HDDs. The Tom's Hardware article was very clear: "...our purpose here is to call into question the idea that SSDs are definitely more reliable than hard drives".

 

[redheeler]

Both SSD and FD have *many* parts which can fail. They both contain many chips -- microcontrollers, RAM, capacitors, PCB, etc.

So it's not like one part that can fail vs two parts -- it's like 98 parts vs 99 parts.

This helps explain why historically SSDs have had substantial failure rates, although generally less than HDDs. The Tom's Hardware article was very clear: "...our purpose here is to call into question the idea that SSDs are definitely more reliable than hard drives".

I don't know if you're quite understanding how a Fusion drive works. There are two drives inside a Fusion drive, and both contain similar parts to what you described. Hence where the 2x failure rate comes from.

It's not like you don't see HDDs with failed controllers but nothing physically wrong with the drive either. It happens.

 

[johnnyturbouk]

No real comparison.
After using a pure SSD solution since 2009 i could not go back. Tried fusion, but i found it appreciably slower in a number of different scenarios.

My current solution is SSD for osx, home and boot files, USB3/TB SSD for storage.

 

[joema2]

I don't know if you're quite understanding how a Fusion drive works. There are two drives inside a Fusion drive, and both contain similar parts to what you described. Hence where the 2x failure rate comes from.

It's not exactly 2x the failure rate, rather the formula is:

1-(1-r1)*(1-r2)..., where r1=drive 1 failure rate in %, and r2=drive 2 failure rate in %

So if the SSD portion and HDD portions of a Fusion Drive have a 1.5% and 5% annualized probability of failure per year respectively, the total annual probability of failure would be:

1-(1-0.015)*(1-0.05) = 6.4% per year

However we aren't comparing a pure 128GB SSD to the exact same make, model and batch of 128GB SSDs when connected to a HDD. Rather it's one certain 128GB SSD + one certain HDD vs a totally different SSD from 256GB to 1TB in size.

As stated in the Tom's Hardware article, some HDDs apparently had a 1.3% failure rate, and some SSDs 6% failure rate. So by that reasoning from a reliability standpoint you'd be better off with a pure HDD.

The problem is you never know what the reliability is of the specific make and model of SSD or HDD. Both types have historically had very wide swings in reliability. However if the batch of 128GB SSDs used in Fusion Drive were highly reliable and the HDD likewise, you could conceivably have cases where FD is *more* reliable than a poor batch of larger SSDs. I don't think that's probable, just illustrating these situations are more complex than first appears.

 

[Butchie-T]

I'm mulling over a new riMac with either a 3TB fusion or 512GB SDD with an additional external drive solution. Difference of around $200 between the two.

The one nag that I have is the fact that you can only add one additional partition to the fusion configuration. I would lean towards wanting to carve that 3TB drive into more than just two partitions.

I wonder why the limitation of only a single additional partition with a fusion configuration, anyone know?

http://support.apple.com/en-us/HT202574

 

[joema2]

I'm mulling over a new riMac with either a 3TB fusion or 512GB SDD with an additional external drive solution. Difference of around $200 between the two...

If you are OK with using an additional external drive, and if the price is only $200 between SSD and 3TB Fusion, I'd just get the SSD. I have two Fusion Drive iMacs and two SSD MacBooks plus a Windows PC with 1TB SSD. Fusion Drive works very well but in general if the cost difference is affordable and you aren't forced to use a slow bus-powered USB 3 portable drive, I'd go with SSD.

 

[marzer]

I'm mulling over a new riMac with either a 3TB fusion or 512GB SDD with an additional external drive solution. Difference of around $200 between the two.

The one nag that I have is the fact that you can only add one additional partition to the fusion configuration. I would lean towards wanting to carve that 3TB drive into more than just two partitions.

I wonder why the limitation of only a single additional partition with a fusion configuration, anyone know?

http://support.apple.com/en-us/HT202574

That limitation is only through Disk Utility. Using the command line form, diskutil, you can add as many partitions as you want. You can even resize the Fusion Drive without deleting your data. There's quite a lot of flexibility in what you can do. Of course, back everything up first cause just in case, there's a bit of a learning curve. But very handy once you get the hang of the Core Storage features.

 

[JustMartin]

It's not exactly 2x the failure rate, rather the formula is:

1-(1-r1)*(1-r2)..., where r1=drive 1 failure rate in %, and r2=drive 2 failure rate in %

So if the SSD portion and HDD portions of a Fusion Drive have a 1.5% and 5% annualized probability of failure per year respectively, the total annual probability of failure would be:

1-(1-0.015)*(1-0.05) = 6.4% per year

However we aren't comparing a pure 128GB SSD to the exact same make, model and batch of 128GB SSDs when connected to a HDD. Rather it's one certain 128GB SSD + one certain HDD vs a totally different SSD from 256GB to 1TB in size.

As stated in the Tom's Hardware article, some HDDs apparently had a 1.3% failure rate, and some SSDs 6% failure rate. So by that reasoning from a reliability standpoint you'd be better off with a pure HDD.

The problem is you never know what the reliability is of the specific make and model of SSD or HDD. Both types have historically had very wide swings in reliability. However if the batch of 128GB SSDs used in Fusion Drive were highly reliable and the HDD likewise, you could conceivably have cases where FD is *more* reliable than a poor batch of larger SSDs. I don't think that's probable, just illustrating these situations are more complex than first appears.

I agree, but it's even more complicated than that. The tom's hardware appeared to be looking at disk farms that were all SSD or all HD to judge the comparative failure rates. The difficulty when you are looking at Fusion Drives is judging where the activity takes place. If I write a 1 block file that goes to the SSD and if I read it regularly, then it stays there - so no HD activity involved at all. If I get tired of reading it, eventually that block gets moved to the HD. So, my single original write has turned into two writes. Then, the next x times I read that file it will involve HD activity until it again gets moved to the SSD portion.

So, what I'm trying to say is that if you're trying to judge relative failure rates based on activity - it's tough. If we had a relative failure rate of 1.5 and 5 but that was based on activity and the SSD portion is used 10 times more than the HD, what does that do to the reliability? Doesn't the fusion drive then become as reliable as a pure SSD?

 

[Butchie-T]

If you are OK with using an additional external drive, and if the price is only $200 between SSD and 3TB Fusion, I'd just get the SSD. I have two Fusion Drive iMacs and two SSD MacBooks plus a Windows PC with 1TB SSD. Fusion Drive works very well but in general if the cost difference is affordable and you aren't forced to use a slow bus-powered USB 3 portable drive, I'd go with SSD.

I am leaning more towards the internal SSD solution with external drives. I'm good with external drives connected to the Thunderbolt ports as, for me anyway, that access is pretty darned quick. Thanks for the info.

That limitation is only through Disk Utility. Using the command line form, diskutil, you can add as many partitions as you want. You can even resize the Fusion Drive without deleting your data. There's quite a lot of flexibility in what you can do. Of course, back everything up first cause just in case, there's a bit of a learning curve. But very handy once you get the hang of the Core Storage features.

Disk Utility limitation, good info to know, thanks for that. I'll start mucking with the command line diskutil and get familiar with it.