iMacs and Fusion Drives

[Marcus Moore]

The way a Fusion drive is set up is to give SSD speeds to your most used files and applications. The spinning disk portion is essentially there as an overflow for those files and applications that need to live on your MacHD, but are accessed so infrequently that they’d just be eating up space unnecessarily on your SSD.

In another year or two as SSD prices come down these will become redundant, but I figure Apple will get 3-4 years out of the technology.

Just like always, never run projects/events/media on this drive if you’re looking for good performance.

[Howie Young]

Marcus,

Thanks for responding to my post. Is it worth it to spend the extra money and get the SSD drive even though it is smaller than the fusion drives?

[Marcus Moore]

That depends on how good you are about file organization. When I bought the final-generation 17″MBP, I ponied up $1,100 for the SSD drive. Very worth it.

That said, you should look at realistically what you need to keep on your system drive and buy accordingly.

I’ll probably be able to save a bit of money on the new MacPro by NOT investing in a massive internal SSD. I doubt I’d buy anything bigger than a 750GB even if it was offered. As long as you have enough space for the OS, your applications, and the usual advised headroom, you don’t need a ton of space. I keep everything else on external drives- Dropbox, iTunes Library, etc. If it’s a work machine, try to keep the MacHD as clean and uncluttered as possible.

[Erik Lindahl]

I think as a concept the fusion drive could live for a long time.

2012-2013: 128GB SSD + 2-3TB HDD
2013-2014: 256GB SSD + 2-4TB HDD
2014-2015: 512GB SSD + 2-4TB HDD

And so forth. The larger the SSD-portion the more the HDD-portion becomes pure “archival” storeage. I think a few tech-savvy sites noted the 128 GB portion Apple uses today is a little on the low side.

[Mark Dobson]

[Howie Young] “For those editors using a 2012-2013 iMac with a fusion drive, have you had any issues or problems with the fusion drive while editing with FCP X?”

I’ve got the 1TB Fusion Drive and have had absolutely no problems since I bought it 9 months ago. I predominately use my iMac for editing with FCPX and the combination of the 3.4 GHz Intel Core i7 with it’s fusion drive running in conjunction with with a GTech 8TB Thunderbolt Drive has given me a superb editing platform.

I’m editing full 1080P and rendering as I go with no major problems. Whilst I still have the occasional spinning ball crashe and use preference manager on a regular basis I put this down to the large number of Plug-ins I’ve got installed on the system.

It’s hard to separate out what is giving me his great performance, the processor, the thunderbolt drive or the fusion drive?

My only concern is the size of the Fusion Drive, does one really need such a large Boot drive? I’ve been used to 320GB core drive and to keeping all my media on external drives.

After 9 months I’m up to almost 400 GBs on the drive. I’ve found that the more space I have , the less efficient I am at housekeeping.

[Rick Lang]

Marcus:
“I’ll probably be able to save a bit of money on the new MacPro by NOT investing in a massive internal SSD.”

SSDs with conventional SATA 6G mounted externally as in a RAID connected to the host via Thunderbolt are going to become commonplace if and when prices fall and most people are working in greater than HD video.

In terms of the new Mac Pro and some other current computers, it would see that the option of having PCI-attached flash memory with even greater throughput than 6G SSDs, will be very attractive in some situations and put pressure on these computer manufactures to provide ever greater volumes. Hybrid SSD/HDD seem like a good idea now but will be a step toward completely removing internal spinning hard disks for high-end configurations shortly using PCI flash storage.

I think the trend to PCI flash will take off with the release of the Mac Pro if the machine is capable of satisfying high-end users. To do that requires a lit of third-party software and hardware vendors to work on the assumption that they will either provide software that runs very well on OpenCL/GL or provide hardware that can function well over Thunderbolt at some point. It is important for Intel and Apple to advance Thunderbolt quickly to get to 100 Gb/s to at least approach enabling PCI design specs which I understand can reach 128Gb/s at least in theory.

Edit: corrected references to Thunderbolt and PCIe GB/s to Gb/s.

Rick Lang

iMac 27” 2.8GHz i7 16GB

[Christian Schumacher]

[Rick Lang] “SSDs with conventional SATA 6G mounted externally as in a RAID connected to the host via Thunderbolt are going to become commonplace if and when prices fall and most people are working in greater than HD video.”

Thunderbolt is currently capped at 1000MB/s, so even if you pony up and go for the SSDs you’re loosing money there as HDDs perform the same on TB RAIDs. Bad news is that apparently TB2 won’t be much better than that.

https://www.barefeats.com/hard167.html

“Like all Thunderbolt devices, the transfer speed of 10 gigabit per second translates to something less than 1000MB/s — even if you load it up with eight 6Gbps SSDs capable of a combined speed of 4000MB/s. And, as you can see, even with eight 6Gbps HDDs capable of a combined speed exceeding 1200MB/s, they don’t come close.”
(…)
“SSDs generally handle small random transactions much faster than HDDs. However, in the case of the ARC-8050, the aggregate random transfers per second is so close, one questions the need for solid state drives.”

[Erik Lindahl]

HDD vs SSD depends on what you’re doing also. Random r/w will be vastly supperior on SSD and Tb2 has 2X the speed of Tb 1. At 1600-1800 Mb/s I have a hard time seeing that being a limit for storeage. Getting to 2GB/s requires a lot of HDD’s

[Rick Lang]

Thanks for the benchmark, Christian. Certainly interesting in that scenario there isn’t a good benefit to justify the expense of SSDs. I think that test appears to be using 4K transfers over TB1 which may not represent the demands of working with video as I would think longer transfers could be used and does not show the performance using TB2, however that may not be a huge improvement. That’s why I suggested the 100 Gb/s Thunderbolt may be necessary to take more advantage of the fastest external devices.

Rick Lang

iMac 27” 2.8GHz i7 16GB

[Howie Young]

Hi Christian,

Thanks for contributing to my post.

Would you advise against getting the SSD as the system drive in an iMac and opt for a fusion drive?