I can't write to my Mercury Accelsior SSD

I just got my Mercury Accelsior SSD and plugged it into it's PCI slot. It was able to recognize it, so I erased the drive and then formatted it to be MacOS journaled. I then tried to use the Black Magic speed test and it said this drive isn't able to be written to. Then I tried booting from it after creating a Super Duper copy of my current SSD, which is bootable, and it still didn't boot to it after selecting it in target disk mode.

Mac Pro, OS X Mountain Lion (10.8.4), 2008, 18 GB RAM, 1 TB HDD, 2.8 Xeon

Posted on Jul 23, 2013 6:33 AM

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13 replies

Jul 23, 2013 6:43 AM in response to Blake Mason

I read somewhere that you have to make a change to allow Black Magic speed test.


As for booting, or cloning etc sometimes yes, sometimes no, and I would use CCC as it will put the recovery partition on there. And sometimes it works best to install in a drive bay or elsewhere and then just move the SSD (may not be an option with yours, you may need to install instead of use SuperDuper) why I am not sure.


Also takes longer with some PCIe boot cards and can add what seems now like a long time, 30-40 seconds longer.


Also your Mac 3,1 has 2 x 16x slots but two others are PCIe 1.1 4x and make sure the 2008 works in those slots.


I chose Sonnet Tempo and Samsung 840s after reading up on the various cards.


Real world experiences with Sonnet Tempo Pro and 2 Samsung 840 Pro SSDs


http://forums.macrumors.com/showthread.php?t=1605500


Sonnet Tempo Pro

http://www.sonnettech.com/product/tempossdpro.html

http://eshop.macsales.com/item/Sonnet%20Technologies/TSATA6SSDPR/

http://eshop.macsales.com/item/Sonnet%20Technologies/TSATA6SSDE/


Sonnet Tempo SSD Pro vs OWC Accelsior (benchmarks)


And after you clone, run Disk Utility's REPAIR DISK on the SSD -- just to be on the safest side.

http://www.macupdate.com/app/mac/37852/trim-enabler


Trim is must-have feature for most Solid State Drives. It not only increases data writing speeds, but it increases the lifetime of the SSD itself. With Trim Enabler, you can bring that feature to Mac OSX. It’s as easy as flipping a switch.

Trim Enabler can also analyze your drive and show information about it’s health and show lifetime statistics.

http://www.groths.org/trim-enabler/

Jul 23, 2013 6:53 PM in response to The hatter

I think it has something to do with the software. I cloned my 1TB drive to my 2.5" 60GB SSD and it worked like a charm as a bootable drive and so have many others (Super Duper also copies the recovery partition). The thing is it won't boot from it even if its the only drive in the machine. I then tried completely erasing it and sticking in the install disk and installing snow leopard. It told me it couldn't be installed to this computer.


I'm basically following Leo Laporte's upgrade tutorial: http://youtu.be/r4umTWEfr4s


I also have a RAID caddy that holds two 2.5" SSDs (http://www.amazon.com/Syba-2-5-Inch-Caddy-PCI-Express-SD-PEX40044/dp/B005MN2GQQ/ ref=sr_1_5?ie=UTF8&qid=1374630159&sr=8-5&keywords=Raid+card+SSD) since it works with Linux I thought why not since they're both on the Unix platform. I put the 60 GB SSD that's bootable in the RAID caddy and it wouldn't boot from it either, basically having the same problem.


So what I'm thinking is that it's the software, or that I have some step missing. The cards have been plugged into the 16x slot where it's supposed to be.

Jul 23, 2013 7:27 PM in response to Blake Mason

I have an Accelsor which I combined with a 1TB hard drive to form a Fusion Drive. I don't know where they were getting there data from but I was able to get the same BlackMagic benchmarks that I got on the Accelsor by itself with the Fusion Drive. I saw no degradation at all that they spoke about in their video.


I have been running with it now for the last two months and it is has been great for me. The CoreStorage is able to promote data to the Accelsior and demote other data to the hard drive in background between my hits to the computer. So far it has managed to do all of its magic without me ever seeing the hard drive.


So far the Accelsior has been one of the easiest pieces of hardware I have ever worked with.


Allan

Jul 23, 2013 8:27 PM in response to Blake Mason

I mounted the 1TB disk in a sled in drive bay 3.


The commands to create the tiered logical volume found both of them without any problems.


The direction at http://blog.macsales.com/15617-creating-your-own-fusion-drive take care of everything.


The only thing to remember is that the commands reformat the two drives into a single logical volume so all data on both will be lost. A backup is a good plan.


Allan

Jul 26, 2013 9:01 PM in response to Blake Mason

Is that only a 64GB drive? That SSD is likely choking on deleted data.


Using another drive as system, I suggest you Download, Install, and Enable TRIM Enabler, then Restart to activate it. Then do a Disk Utility (Repair disk) of the SSD from that other System. You will see a message near the end of the process "trimming unused blocks" and a delay of up to a minute while it completes.


http://www.groths.org/trim-enabler/



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The other approach is to restart, but do not access the drive for at least 20 minutes, during which time it will do one cycle of garbage collection. This may improve things slightly. You may have to repeat the process.

Jul 26, 2013 10:03 PM in response to Grant Bennet-Alder

The problem with that is, I have a 60 GB 2.5" SSD that boots in the SATA port, but when I put it in my RAID caddy that handles 2.5" drives it is having the EXACT same problem down to the Mountain Lion installation. So it has to be something to do with Mountain Lion and PCI usage.


It has nothing to do with garbage collection? I've never even heard of that.

Jul 27, 2013 8:10 AM in response to Blake Mason

That guy wrote about the Restore feature (of Disk Utility), but said it would not work for a bootable disk. This is because Restore copies only a single Volume/Partition at a time. To make a drive bootable, you need the normal, visible Volume/Partition, typically "Macintosh HD" AND the EFI_Boot partition, normally hidden.


Topher Kessler wrote a nice discussion about how to enable the debug features so that you can enable "show every partition":


http://reviews.cnet.com/8301-13727_7-20081463-263/manage-all-partitions-with-dis k-utility-in-os-x/

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I can't write to my Mercury Accelsior SSD

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