SSDs/HD Combo to create a Fusion Drive???

[Mr-iMac]

I asked this question on the Apple web site and didn't get any answers from anyone. One guy gave some decent opinions, but no real answers, so I'm posting it here. It seems to me the "experts" on the Apple site are more suited to questions like "how do I plug my printer into my computer." Sort of sad, really.

In any case, one of our systems is a 2009 MacBook Pro, 13". We started getting a lot of spinning beach balls and I/O errors on it, so we used Scannerz (http://scsc-online.com/Scannerz.html) to check it. The drive failed. Bad sectors spanning a 5 GB range on the drive. We're tossing the drive..as far as I'm concerned, it's dead.

A local computer store has some Sandisk SSD for dirt cheap (about $55.00 for a 65GB model.) 65GB isn't going to cut it space wise, but I started thinking maybe we could create our own Fusion drive. I found this article telling how to use disk utlity in ML to create (at the very least) a volume group:

http://reviews.cnet.com/8301-13727_7-57550128-263/how-to-make-a-custom-corestorage-drive-in-os-x/

Here are some of my questions:

How good are SSDs, really? I know they're fast but a lot of people seem to have problems with them "disappearing" for no known reason. Some even seem to suffer more block corruption than real HDs. I know this is still an "emerging technology" but I'm not in the mood to be a guinea pig for SSD makers!

Does the linked article above actually create a Fusion drive, or just a volume group? It isn't clear whether a true Fusion drive is a volume group AND control software that maps data between the HD and SSD, or whether just being a volume group does it.

We're figuring the 65GB SSD along with a 320 GB HD would make a good combo ... fairly low price, high performance.

How does a Fusion compare to a stand-alone SSD performance wise?

I'd really appreciate the opinions of anyone that's tried this. I would have thought the SSD would have been like a super high speed cache, but this isn't the case. Volume groups are nothing new (at least to anyone that knows anything about Unix systems) but is the set up described in the CNET article REALLY a Fusion drive? Apple seems to be keeping the technology behind it somewhat of a secret.

Thanks.

 

[jav6454]

It's a good idea to do. Many people swap out their DVD-Drive for an Opti-bay and put an HDD in there.

SSD in the main drive and they let their Macs go. It's not a perfect Fusion drive as you don't get the OS to know exactly which files should go where (most used into SSD). However, it is a bit more perfect in a sense of control. You control which files, programs or pictures go where.

That way you maximize your SSD performance vs using the massive space in the HDD.

I have to point out that while it is true that SSD technology is emerging, it has been doing so for 5 years already. That said, there are several drives out there that have been proven rock solid. Example are the Samsung 840 drives, very well built and reviews have nothing but praise for them.

As per corruption on an SSD, it is a rare event and it is more likely that you will suffer from write speeds slowdowns and eventual page failure due to maximum writes before a corrupt page appears. Moreover, given regular use, your SSD is bound to die within 10-15 years of reads/writes.