MacOS – Dual booting Mid 2012 Macbook Pro multiple SSDs Errors

This is my 2 cents worth. I have no specific experience for Samsung SSDs but I do have a fair amount of experience with Mac Laptops and MacMinis with SSDs.

I am post specifically because I have been fighting with an apparently "similar issue" and have come to the conclusion that SSDs are more tricky than hard drives fro a troubleshooting point of view. I have had to return a few SSDs to the manufacturer ( distributors ). In fact, I returned one to OWC just today that has resisted attempts to update it's firmware - twice over several months and began exhibiting poor performance and I was having kernal crashes that I believe were SSD related. I use a utility called "Trim Enabler" for two reasons: 1) I like to watch metrics that perhaps give insight on storage health - the observable health parameters of the SSD and a second Harddisk on my 2012 MacBook Pro and 2) because it turns on the Trim functionality which SOME SSDs like ( need ) or something....

While OWC ( macsales.com ) is a Mac specialty supplier and appear to be experts and have been good to me over the years, but in this case of SSDs, they have failed to come up with a way that I have access to test my own SSDs or a surefire efficient way to identity if the SSD is the issue or if firmware update will help and thus I returned the SSD today and replaced it with a Crucial SSD which uses different firmware - Sandforce firmware. I have experience with the Crucial SSDs for almost 4 years on Mac's and they seem to work well. It was Crucial who told me to used the 3rd party software called Trim Enabler to "enable trim" after I experienced significant performance issues that Crucial tech support believed was because the SSD was not doing necessary maintenance on itself - i.e. Trim.

Now with all that said, I believe there is still a bit of black magic going on - perhaps it is just marketing and/or marketing secrecy so that SSD makers secret sauce does leak out. Personally, I don't like the effects of the secret sauce on the end user's ability to get genuine information and tech support so they can make informed decision on their purchases of SSD.

Even so, I might recommend you try a OWC or Crucial SSDs based on those companies recommendations and warrenty policies. I no long expect trouble free saling or perfect performance or zero maintenance for a busy SSD. I have never done firmware updates on hard disks but SSDs appear to need these firmware tweeks.

I would love some genuine information at the global statistics level, so that I can better gauge my experience against what the global pool experience is showing.

If you are using something like the Optibay drive from MCE Tech, you an put either drive in the caddy. I prefer to make a single change at a time, so when I did this I put the new drive in the caddy and left the old working boot drive alone.

As for installing from a USB thumb drive (I assume this is what you meant since you weren't clear), you shouldn't have to. You can download the Mountain Lion installer and run the app. During the install process you can choose what drive to install the OS on, simple choose the newly installed and formatted SSD.

Once you have both OS installed, the system will remember the last drive that was selected in the Startup Disk preferences and store that choice in NVRAM so that it will continue to start from the preferred drive. You can hold the option key at boot to prevent this choice and pick from all bootable drives when you want to switch things on a specific boot.

Most people find that having two OS internally is confusing. Spotlight will try to find the correct version of Safari if you don't keep them both updated, but sometimes you end up running the wrong version of an app. This is confusing at best, and troublesome most of the time and can cause data issues when the wrong version of an app opens data it didn't expect from a newer version of iPhoto for instance.