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Beau Nash

macrumors newbie
Original poster
Nov 13, 2012
20
0
York, UK
Right. I'm waiting on a 2.6GHz i7 with 1TB internal HDD to which I'm adding RAM (to 16GB) and an internal 256GB SSD.

I'd planned on keeping the SSD as a separate drive on which I'd put the OS, Apps other things like my Lightroom catalogs and Aperture libraries (as you do). Images will be stored on an external FW800 drive.

But what if I partitioned the SSD into two 128GB drives and used the ML Core Storage facility to create a fusion drive as well? I've read a lot about the advantages of letting the OS shift data around to optimise performance in FDs. [EDIT in light of comment below - fuse SSD partition with HDD].

So, doable? A disaster waiting to happen? Worthwhile? A complete waste of time?

What does the panel think?
 
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Beau Nash

macrumors newbie
Original poster
Nov 13, 2012
20
0
York, UK
Do you want to "fuse" the two 128 GB partitions on the same SSD to a Fusion Drive or one 128 GB plus the HDD volume?

Sorry, I should have said - fuse the SSD partition with the HDD.

Actually, the more I think about it, the more I think that a 256 SSD with headspace for apps or even fusing the whole lot would be better than my suggestion but I'd still be interested to hear others' views.
 
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Ubele

macrumors 6502a
Mar 20, 2008
688
121
I've been doing a lot of research on options for upgrading the storage of my new Mac mini, and I haven't come across anyone who has done what you propose. I don't know if it's possible. I know that you can't create a Fusion drive from an external SSD; both drives need to be internal. If you install an internal SSD and HDD, OS X assumes you have a broken Fusion drive and will want to rebuild it. If you want to keep the two drive separate, there are Terminal commands you can enter. But I don't know whether you can partition an SSD and use one partition plus the HDD to create a Fusion drive. I'm guessing not, but I could be wrong. I don't know what the advantage would be, though.

Based on my research, I've determined that people fall into one of two groups: 1) those who don't trust the Fusion drive and prefer to manage files themselves on a separate SSD and HDD, and 2) those have done so in the past or could do so, but who can't see spending the time and effort to do what the Fusion drive algorithms do just fine. I fall into the second group: there are a couple of situations in which a separate SSD/HDD would provide a speed advantage, but that would be outweighed by the time I'd spend managing files. I plan to get a 512 GB SSD when I find a good sale, and create a 1.5 TB Fusion drive. The majority of my files would remain on the SSD. I think you'd be fine creating a 1.25 GB Fusion drive.
 
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eyepea

macrumors member
Jul 20, 2012
91
0
Comment

Beau Nash

macrumors newbie
Original poster
Nov 13, 2012
20
0
York, UK
This one talks about creating a fusion of the partition (not disk) of an SSD and an HHD (i think?). I think he is suggesting creating a fusion drive of you SSD but leaving the recovery partition 'outside' the fusion. This might be similar to what you want to try.

I came across this when I was looking at the fusion techniques. Haven't tried it though.

http://robteix.com/2012/11/09/rolling-out-your-own-fusion-drive-with-the-recovery-partition/

Thanks again, eyepea. Useful stuff.
 
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Fishrrman

macrumors Core
Feb 20, 2009
21,676
7,890
"So, doable? A disaster waiting to happen? Worthwhile? A complete waste of time?"

I think "a complete waste of time" is the most appropriate answer….
 
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Beau Nash

macrumors newbie
Original poster
Nov 13, 2012
20
0
York, UK
"So, doable? A disaster waiting to happen? Worthwhile? A complete waste of time?"

I think "a complete waste of time" is the most appropriate answer….

Yup, I think I agree.

I'm actually coming round more to the idea of fusing the two drives as a whole but I'm still interested in others opinions and experiences.
 
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Beau Nash

macrumors newbie
Original poster
Nov 13, 2012
20
0
York, UK
In fact the more I think abut, the dafter an idea it is. The OS would probably just treat the extra SSD partition as another spindled drive so I'd waste 128GB of SSD as well as wasting time.

So the next question is to fuse or not to fuse? I think a 256GB/1TB FD would be pretty snappy but so would 2 drives with the HDD used for just data.
 
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Mike in Kansas

macrumors 6502a
Sep 2, 2008
962
73
Metro Kansas City
Setting it up as Fusion would allow for the most efficient use of the array at the block level and not require you to manage it. It would run itself, and constantly automatically optimize the split of blocks between the SSD and HDD as you used applications, files, etc. You give up some control, similar to keeping all of your original photos and edits in an Aperture library.

Keeping it separate would give you the ability to control exactly where you keep every little thing on your system at the file or application level. You can move things around at your heart's content, and constantly try to manually keep your system optimized based on changing usage, files sizes, etc. You maintain all control, similar to keeping all of your original photos and edits in a folder hierarchy.

I used to do the latter and now employ the former. After fusing my internal 240GB SSD with an external 2TB FW800 HDD, I will never got back to an "un-Fused" system until SSD prices come down substantially and can afford a 2TB or larger SSD. I've also moved away from hierarchical photo, video and music storage and instead enjoy Aperture, iMovie and iTunes.

The biggest reason NOT to do it (aside from giving up some control) would be if you frequently moved around very large files (>4GB) and wanted to always take advantage of them being on the SSD.

And contrary to what someone posted above, you CAN Fuse an external drive and an internal drive. As a matter of fact, you can Fuse 2 external drives. Somebody early on when Fusion first came out played around with Fusing 2 thumb drives. If it has a drive name, it appears that you can Fuse it.

I've had mine arranged like this for 2 months. I have about 800GB of capacity of my 2.2 FD array taken up. I have enjoyed it immensely.
 
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hfg

macrumors 68040
Dec 1, 2006
3,597
285
Cedar Rapids, IA. USA
Right. I'm waiting on a 2.6GHz i7 with 1TB internal HDD to which I'm adding RAM (to 16GB) and an internal 256GB SSD.

I'd planned on keeping the SSD as a separate drive on which I'd put the OS, Apps other things like my Lightroom catalogs and Aperture libraries (as you do). Images will be stored on an external FW800 drive.

But what if I partitioned the SSD into two 128GB drives and used the ML Core Storage facility to create a fusion drive as well? I've read a lot about the advantages of letting the OS shift data around to optimise performance in FDs. [EDIT in light of comment below - fuse SSD partition with HDD].

So, doable? A disaster waiting to happen? Worthwhile? A complete waste of time?

What does the panel think?

Yes, what you propose is easily doable, and I have done it several times. Simply follow any of the posts or links showing how to create a DIY Fusion drive, and use the "Disk/Partition" ID (i.e. disk0s1) rather than just the "Disk" ID (disk0). I usually do this to have a Windows partition on the SSD, with the remaining SSD joined with a HD for a Fusion drive. It works great!.


-howard
 
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