organicCPU said:

Any 2,5" SATA III (6.0Gb/s) SSD would work. In my MBP 2012 there has been one from Crucial, then moved to Samsung 850 EVO, then to Samsung 860 Pro. If you need a cheap, but still reliable solution, maybe try some of the Samsung 860 EVO models.

organicCPU said:

My first switch from Crucial to Samsung was an exchange under warranty and for trying to force a possibly disk drive controller related bug in Photoshop, but with no avail. The SSD from Crucial even felt a bit snappier before and after the unnecessary switch, it took a couple of days to get used to the slightly different response from the Samsung EVO, though it was still very fast and soon I didn't look back.

The second switch from EVO to PRO was mainly for expanding the size from 1 TB to 2 TB.

Then the PRO has reports of a minor performance gain while continuously writing large chunks of data, compared to the slightly slower caching EVO. For me there was no noticeable speed difference as I don't use it particularly for video editing or similar.

There is a technology difference between the PRO and the EVO, too. The PRO uses 3D-V-NAND MLC (Multi-Level Cell) and the EVO comes with triple-level cell flash (TLC). It is said that MLC is more robust and thus lasting for a longer time and a higher amount of reads and writes. As I'm doing backups on a daily basis, I hope that it won't matter much for me if the drive breaks or not.

Plus, the next generation of SSD in several years will probably be even faster and will have a higher capacity. Then this will assumably be a good reason to deal with switching to another next drive, long time before something could crash ;-) Replacing a drive every 4 to 5 years has always been working for me. That's why I always keep switching…

However, you'll do everything right with going for a cheaper Samsung EVO and not for another more expensive model. If you do have average user habits, I guess a new EVO would last up to 5 years+ for you, too. Then with an additionally good backup strategy utilizing Time Machine and others, the SSD can crash at any time and you'll always stay safe.

All SSDs and HDDs that I know are a bit scary to maintain. If a particular drive makes no explicit problem like a manufacturer reported data loss, better stay away from firmware upgrades as new bugs get possibly just introduced by an upgrade. Most big SSD manufacturers like Samsung and others don't even provide their customers a user friendly firmware upgrade tool for macOS. Maybe they just fear too many complaints about buggy firmware. I don't want to keep you away from updating software, but in my experience in most cases a drive running with initial firmware usually lives longer.

Most SSDs won't come in macOS flavor. That means, you'll need to reformat the drive before you can use it. You could do that after booting an installer stick or macOS Recovery over the Internet, then select Disk Utility from the macOS Utilities splash screen, format the SSD and simply continue with installing.

My preferred way for installing a macOS is to transfer another one. Therefor I make a bootable clone on an external disk drive, put the new unformatted disk drive inside the Mac, restart, press and hold Option, select the external clone to boot, then format the internal SSD from a normally mounted macOS in Disk Utility. Finally I'm cloning back the external drive to the new internal one. I'm doing that with the help of Carbon Copy Cloner. CCC is copying the Recovery partition as well without cumbersome workarounds. Sometimes I'm preparing a SSD externally in a docking station from RaidSonic and then plug it fully functional.

For you, on a new (used) Mac, a fresh install makes absolutely sense, if you don't have another complete Mac that you could transfer. Even then, sometimes beginning with a fresh install is the best thing you can do to get rid of old unused data.

As TRIM support isn't enabled for a third party disk drives by default, I recommend doing it manually after a successful installation of macOS (if you're installing MacOS 10.10.x Yosemite or higher type into Terminal man trimforce and read about it). Resetting NVRAM and SMC Controller is always another good idea after hardware changes, but probably not a must after just a disk drive replacement.

Hopefully that was not too boring…

Click to expand...

DrBrush said:

I have very little to add to the previous post, but note that you can replace the optical drive with a second hard drive using OWC's data doubler, which is what I have done. But a note of caution there, if you want to boot into Windows with Boot camp, then the boot drive has to be in the original position, so you need to move the original drive onto the data doubler and put the SSD in the original position. For all other uses, the new SSD can go into the data doubler just fine (I found this out after putting the SSD in the data doubler, but my Windows usage was so low I couldn't be bothered to open up and swap them around!).

Click to expand...

b0fh666 said:

just do it, will breathe new life into that 'old but gold' mac.
im running 2 of those as main computers. 16GB, two SSDs (optibay mod) and mojave. no complaints.

Fishrrman said:

Crucial, Sandisk, Adata, even an off-brand name -- just about any SSD will be fine.
Buy "for price".

You also need one of these enclosures:

https://tinyurl.com/y5ucqfaj

It will have two purposes:
1. Use it to "prep and test" the SSD BEFORE you open up the MBP to install it
and
2. An enclosure for the old HDD once you take it out of the MBP.

You will also need CarbonCopyCloner (FREE to use for 30 days) from here:

Download Carbon Copy Cloner | Carbon Copy Cloner | Bombich Software

www.bombich.com

What to do when you have this stuff:

First:
Get the SSD initialized and ready.
a. Put it into the enclosure and connect it to the MBP
b. Open disk utility
c. ERASE the SSD to one of the following:
- if you're using High Sierra or Mojave, use APFS with GUID partition format
- if you're using Low Sierra or earlier, use Mac OS extended with journaling enabled, GUID partition format.
d. Now the SSD is ready for the OS.

Next:
a. Open CCC and accept all the defaults.
b. Put your source (the existing internal drive) on the left
c. Put your destination (the SSD) in the middle
d. Leave the "schedule" box on the right alone
e. Click the clone button and follow through. The clone will take some time
f. IF CCC asks if you wish to clone the recovery partition, YES, you want to do this, follow through.

Then:
Check the SSD for "bootability"
a. Power down, all the way off
b. Press the power on button and IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears
c. Select the external SSD with the pointer and hit return.
Do you get a good boot? It will look EXACTLY as does your HDD. You'll have to go to "about this Mac" to be sure.

Now... if you're satisfied that the clone is good, it's time to open the MBP and "do the drive swap"
a. Go to ifixit.com to see what's involved.
b. BE SURE YOU HAVE THE RIGHT TOOLS. You need a Phillips #00 driver and a TORX T-6 (for the bosses on the sides of the drive)
c. I wouldn't worry about disconnecting the battery
d. It's an easy job, hardest thing is removing and replacing the screws. Take note of the 3 long ones and where they go.

Finally... the moment of truth.
a. Get the back on, tacked on with 4 or 5 screws (for the moment)
b. Press the power-on button and AGAIN do the "option key trick" as mentioned above.
c. Do you get a good boot?
d. If so, GOOD, not finished yet.
e. Go to the finder, select the startup disk preference pane, and RE-DESIGNATE the internal SSD to be the new boot drive.
f. Now, power down, and replace the remaining screws if they're not already in

Then... put the old HDD into the enclosure. It can become either a backup or can be used for extra external storage, stuff you no longer need on the internal drive.

Click to expand...

Fishrrman said:

Crucial, Sandisk, Adata, even an off-brand name -- just about any SSD will be fine.
Buy "for price".

You also need one of these enclosures:

https://tinyurl.com/y5ucqfaj

It will have two purposes:
1. Use it to "prep and test" the SSD BEFORE you open up the MBP to install it
and
2. An enclosure for the old HDD once you take it out of the MBP.

You will also need CarbonCopyCloner (FREE to use for 30 days) from here:

Download Carbon Copy Cloner | Carbon Copy Cloner | Bombich Software

www.bombich.com

What to do when you have this stuff:

First:
Get the SSD initialized and ready.
a. Put it into the enclosure and connect it to the MBP
b. Open disk utility
c. ERASE the SSD to one of the following:
- if you're using High Sierra or Mojave, use APFS with GUID partition format
- if you're using Low Sierra or earlier, use Mac OS extended with journaling enabled, GUID partition format.
d. Now the SSD is ready for the OS.

Next:
a. Open CCC and accept all the defaults.
b. Put your source (the existing internal drive) on the left
c. Put your destination (the SSD) in the middle
d. Leave the "schedule" box on the right alone
e. Click the clone button and follow through. The clone will take some time
f. IF CCC asks if you wish to clone the recovery partition, YES, you want to do this, follow through.

Then:
Check the SSD for "bootability"
a. Power down, all the way off
b. Press the power on button and IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears
c. Select the external SSD with the pointer and hit return.
Do you get a good boot? It will look EXACTLY as does your HDD. You'll have to go to "about this Mac" to be sure.

Now... if you're satisfied that the clone is good, it's time to open the MBP and "do the drive swap"
a. Go to ifixit.com to see what's involved.
b. BE SURE YOU HAVE THE RIGHT TOOLS. You need a Phillips #00 driver and a TORX T-6 (for the bosses on the sides of the drive)
c. I wouldn't worry about disconnecting the battery
d. It's an easy job, hardest thing is removing and replacing the screws. Take note of the 3 long ones and where they go.

Finally... the moment of truth.
a. Get the back on, tacked on with 4 or 5 screws (for the moment)
b. Press the power-on button and AGAIN do the "option key trick" as mentioned above.
c. Do you get a good boot?
d. If so, GOOD, not finished yet.
e. Go to the finder, select the startup disk preference pane, and RE-DESIGNATE the internal SSD to be the new boot drive.
f. Now, power down, and replace the remaining screws if they're not already in

Then... put the old HDD into the enclosure. It can become either a backup or can be used for extra external storage, stuff you no longer need on the internal drive.

Click to expand...

darzo27 said:

Hi, I've been using a WD blue SSD as a boot drive via an external SATA3 enclosure (up to 5gbps) now have put this SSD into a drive caddy in the optical bay (which supports SATA3) however it is extremely slow.
Any ideas why? or workarounds?

There are other posts wrt the issue though I haven't spotted a fix.
Want to use the SSD in the caddy to free up the enclosure.

The MBP was bought used with the original drive removed and damaged ribbon cable hence the need to use the boot drive externally or via a caddy.

Click to expand...