SSD vs Fusion Drive

[SaSaSushi]

yadmonkey wrote:
"TRIM probably isn't going to make a big difference, but for a startup disk there's no question that makes Thunderbolt the only way to go."

Once again, I have to jump in and say that claims like this are not supported by empirical performance stats from the real world.

If I run BlackMagic Speed Test on the drive, it runs as fast today as the day I first booted from it. NO slowdown in performance whatsoever. NONE..

Not to turn this into a TRIM debate but the main drawback of using an SSD without TRIM may be overall longevity of the drives due to the ill effects of write amplification, on top of decreased performance.

The following is from a post to superuser.com by a user named snk that explains it well:

My understanding of this phenomenon is that it affects the longevity of the drive more than it affects the performance, at least from what an end user observes.

SSD media can only write to empty file pages, but they can only erase a file block (collection of pages, normally around 128). Without TRIM (which the OS uses to tell the drive which pages and blocks it can safely erase), the SSD needs to move pages around in order to free up blocks in order to write new data.

What this boils down to is the SSD needs to perform multiple physical writes to do one logical write of the data sent by the OS. This is a phenomenon called Write Amplification.

The longevity issue comes into play when you consider that SSDs have a limited number of write/erase cycles per cell (1,000-100,000 per cell depending on the media). This is mitigated somewhat by wear leveling which is an automatic use of the least-used cells on a drive to avoid uneven wear, but write amplification limits how much wear leveling can take place. Wear leveling also leads to some write amplification on its own (due to needing to move data which is not changing under certain scenarios).

Since there are still no moving parts in the SSD, it will obviously be much faster than a normal drive even with these issues. However, the relative speed to a non-affected drive could be many times slower depending on how much write amplification is taking place.

 

[PharmDoc]

I'm looking to upgrade by late 2009 27 iMac with a 1 TB hard drive. If I purchase a 512 SSD, then I can't restore from a TM backup and have to transfer the files over manually? What would be the best way to accomplish this?

 

[Glockworkorange]

I have a 2014 1 TB iMac 5K which is the 128GB ssd model and 'decent' for the most part since the entire OS runs on the ssd but I hate the fact I pretty much can never run bootcamp. Also the speed could be better when accessing some large file like large photos. I only bought it with the fusion because it was on sale and I would of had to spends hundreds more just to get a 256 SSD so I said screw it. Reality is the 256 gb would have require external storage as well so I would have been in the same spot.

I've been considering purchasing a 2017 iMac and if I do I'm going 1 TB SSD. I still need to wait for reviews to come out and part of me just wants to wait for a refresh of the entire form factor which will probably occur late next year at the earliest.

I have the same 2014 model and also picked it up on sale. Got a killer deal at Adorama.

The machine is generally snappy, but it's annoying when it slows down and reaches into the HDD. You can also hear it happening.

I went with straight SSD at 1 TB for this release.

From most people though, I think a fusion with 128 SSD portion will probably be fine.

As always, depends on what you are going to do with it. I think pure SSD for the OP's purposes is a no-brainer.

 

[jw3571]

If you're using an external, is there a lag when you're pulling up pics or music off the external?

 

[yadmonkey]

If you're using an external, is there a lag when you're pulling up pics or music off the external?

No appreciable lag. USB 3.0 already has more bandwidth than necessary for small files like songs and pics. Photos is really fast and songs open almost instantly.

I'm sure it's technically faster to have these libraries on your internal SSD, but it's still about instant as far as I'm concerned.

 

[Tjmckay4]

I don't know what you use your computer for, but if it were me in your shoes, I'd use the 512GB internal SSD as the boot and application drive, the 850 EVO SSD as cache or scratch disk, and get either a 1TB SSD for active working files or a 2TB black drive for file storage. Then I'd get another for 2TB black drive for a mirrored backup.

I use it for web browsing, productivity apps, viewing jpgs and videos in lightroom and watching 4k video files; nothing too strenuous. I only use 100gb now, for the OS and apps, on my external SSD. What would I use the other 400gb for?

 

[ZipZap]

No appreciable lag. USB 3.0 already has more bandwidth than necessary for small files like songs and pics. Photos is really fast and songs open almost instantly.

I'm sure it's technically faster to have these libraries on your internal SSD, but it's still about instant as far as I'm concerned.

I am sorry but external is in no way as fast as a bus based drive. So if you compare them, yes there is a lag. And the bigger the files, the more noticeable it will be. Plus writes will be slower.

 

[paulryp]

Personally i don't think there is even a debate to be had. 512SSD over the 2TB fusion. 1TB SSD if you can afford it so you can split 600/400 for a bootcamp partition. Then add external for iTunes & media and Archive.

 

[ZipZap]

Personally i don't think there is even a debate to be had. 512SSD over the 2TB fusion. 1TB SSD if you can afford it so you can split 600/400 for a bootcamp partition. Then add external for iTunes & media and Archive.

I think that if you dont want to regret the decisions its:

1TB SSD or 2TB Fusion.

512GB is too small.

 

[paulryp]

Yep agree unfortunately 1TB SSD should be the gold standard now. Which is why its so frustrating that Apple charge such a HUGE premium for it.

 

[sundayx]

Can anyone post their Read/Write speeds on the new 2017 iMac SSDs?

 

[yadmonkey]

I am sorry but external is in no way as fast as a bus based drive. So if you compare them, yes there is a lag. And the bigger the files, the more noticeable it will be. Plus writes will be slower.

Sorry, but context matters. He was asking about small files (pics and music specifically) and I maintain that there is no appreciable difference. I've been operating this way for 3 years and have had my music library on the internal SSD and external. Either way opening a song or pic is instant. Cycling through expanded pics in Photos using the right and left arrow keys is instant - as fast as you can press the key.

Sure, the internal will be faster for large files and is technically faster over all, as I already alluded to. So what on Earth is your point?

 

[smarter]

I ordered my 27" 2017 iMac with the 1tb ssd. It was € 480,- more than the 512gb ssd. My current 2010 27" iMac served me very well over the last 7 years, so I decided € 480,- is well worth it to have a solid piece of solid state disk space bolted inside my mac for future purposes and possibly slightly higher resale value. External storage is cheaper, I know. But I think you can only decide once on the right factory configuration.

 

[Half Rick]

If you're using an external, is there a lag when you're pulling up pics or music off the external?

I don't know about pictures, but I keep my entire iTunes library on a WD MyBook Live, i.e. 5400 RPM HDD connected via ethernet to the router, I experience zero lag when playing music, series, movies... The only exception is if the drive is sleeping, then it'll take a second or two before. But that's not really an issue.
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Can anyone post their Read/Write speeds on the new 2017 iMac SSDs?

I don't know why, but I have to press stop in order to save a screenshot instead of it just stopping and showing the result... Basically, the write speed here is in the very beginning, it always ended up north of 2000 MB/s though.

 

[scoobs69]

I use it for web browsing, productivity apps, viewing jpgs and videos in lightroom and watching 4k video files; nothing too strenuous. I only use 100gb now, for the OS and apps, on my external SSD. What would I use the other 400gb for?

You don't need to use the other 400GB at all. Leave it empty. If you're doing nothing strenuous, then a 2TB USB3 7200 RMP drive will be perfect for your files.

 

[Tjmckay4]

You don't need to use the other 400GB at all. Leave it empty. If you're doing nothing strenuous, then a 2TB USB3 7200 RMP drive will be perfect for your files.

So what about just getting the 2TB fusion? or maybe the mid-tier iMac with the 256gb SSD?

 

[devilsnj30]

I mean I think if I buy one I am going cheap internals and upgrading the Ram and running MacOS onan SSD off USB 3 or Thunderbolt 3. Anyone see a reason I shouldn't. The only thing I WOULD do is buy the 16GB Ram upgrade if I bought the 21 inch. I don't feel like opening the iMac up. I think Apple generally puts seagate in the Fusion Drive computers, at least the 1TB ones and I don't deal with seagate.

 

[Half Rick]

I mean I think if I buy one I am going cheap internals and upgrading the Ram and running MacOS onan SSD off USB 3 or Thunderbolt 3. Anyone see a reason I shouldn't. The only thing I WOULD do is buy the 16GB Ram upgrade if I bought the 21 inch. I don't feel like opening the iMac up. I think Apple generally puts seagate in the Fusion Drive computers, at least the 1TB ones and I don't deal with seagate.

It is of course a simple matter of preferences, and if you feel that is it reasonable for you to go that route - you should.

Personally though, I do the opposite. I have a 512 GB SSD in my 2017 iMac (256 would have been enough, but I had the opportunity to splurge just a little so I did ). I use an external USB 3.0 for CCC-backup (meaning I can boot it from the external drive if I need to) and a NAS as an archive/iTunes library. I want to move away from platter based storage over time, so buying a new computer with a HDD that is not easily replaced by the user simply makes no sense for me, even if I'd run the OS from an external drive.

 

[scoobs69]

So what about just getting the 2TB fusion? or maybe the mid-tier iMac with the 256gb SSD?

I personally wouldn't touch the fusion. If you don't need the 8GB Radeon Pro 580, then yes. Go for the 256GB with the other iMac options. I have a 256GB OWC SSD boot drive on my 2009 Mac Pro, have Adobe CS3 Design Suite, and the Adobe CS6 Design Suite installed, various Capture One Pro 6, 8, 9, and 10, a boat load of other apps and utilities, and I still have 100GB available.

If you need the 8GB video card, then the lowest SSD option you can buy is the 512GB SSD.

To me it's an idiotic move for Apple to not offer the 256GB SSD with the Radeon Pro 580.

 

[met985]

I'm just wondering what to do with the hard drive of the new iMac I'm gonna order even I think I'll choose the 2 tb fusion drive (on the top 27" iMac). Anyway before placing the order I'd like to understand if the hd part of the 2tb fusion is 7200rpm or 5400; I tried to find some information without success.

 

[cmbarclay]

I'm just wondering what to do with the hard drive of the new iMac I'm gonna order even I think I'll choose the 2 tb fusion drive (on the top 27" iMac). Anyway before placing the order I'd like to understand if the hd part of the 2tb fusion is 7200rpm or 5400; I tried to find some information without success.

It's 7200 rpm it just checked my system info. I have the new iMac with 2tb fusion. I have to be honest compared to my late 2016 MBP w/2tb ssd it's slightly sluggish.

 

[met985]

It's 7200 rpm it just checked my system info. I have the new iMac with 2tb fusion. I have to be honest compared to my late 2016 MBP w/2tb ssd it's slightly sluggish.

Thank you for the reply. Is it something so noticeable? For sure ssd is faster but 2tb fusion should be a good solution for speed and storage capacity without having troubles in the daily use. Which iMac do you own? I would choose top 27" with i7

 

[Half Rick]

Thank you for the reply. Is it something so noticeable? For sure ssd is faster but 2tb fusion should be a good solution for speed and storage capacity without having troubles in the daily use. Which iMac do you own? I would choose top 27" with i7

Is your day-to-day usage able to fit in the 128 GB SSD portion? Then it's okay. If not, I'd advise you to get an SSD and use external drives for storage capacity.

I'm not against fusion drives per se, but if you need to access the platter based part on a daily basis you'll probably end up wishing you'd gone the SSD route...

 

[met985]

Is your day-to-day usage able to fit in the 128 GB SSD portion? Then it's okay. If not, I'd advise you to get an SSD and use external drives for storage capacity.

I'm not against fusion drives per se, but if you need to access the platter based part on a daily basis you'll probably end up wishing you'd gone the SSD route...

I suppose it will fit; apart from the standard use (web browsing / mail / etc) I will use it to record music or maybe to do something with photoshop or small videos so the 128 GB SSD will be enough. I already have some old hd which I can use as external drives or anyway I can buy one new ssd to speed everything up.
I'm planning to buy at least 16 gb ram in order to increase it up to 24 gb so I shouldn't have any lag or big troubles.

 

[Half Rick]

I suppose it will fit; apart from the standard use (web browsing / mail / etc) I will use it to record music or maybe to do something with photoshop or small videos so the 128 GB SSD will be enough. I already have some old hd which I can use as external drives or anyway I can buy one new ssd to speed everything up.
I'm planning to buy at least 16 gb ram in order to increase it up to 24 gb so I shouldn't have any lag or big troubles.

Then go for it I went from a regular HDD to a fusion drive to an SSD, and several times per day it was like being back on the HDD with the fusion drive, whereas the difference moving from a fusion drive to a pure SSD solution was like night and day. But I mean, this is based on my personal usage pattern so I am in no way saying you'll experience the same thing.