Boot From OSX External SSD Thunderbolt or UBS 3.0

[nambuccaheadsau]

I used a Silicon Power 240GB TB drive externally also on a 2011 iMac as the 7200rpm was slow aftre coming from a Mac Pro. Cloned OS over in 2012, and used the TB drive until replaced the machine with no problems at all. Well, maybe one. I kept the internal as backup drive, and for some reason software updates went to it first, then a reboot as per usual installed the update on the external.

No heat issues whatsoever and I avoid Samsung everythings!

 

[SaSaSushi]

I've never used Samsung SSD's.
I've purposely avoided them, because -- even though the high-end models yield some of the fastest performance -- they seem to have more reported problems than do other drives, at least from reading posts here.

Oh, now it's Samsung's fault.

I've been running this iMac off a Samsung 840 EVO in a Delock TB enclosure for three and a half years now and haven't had a hiccup. TRIM enabled from day one and benchmarks as fast as ever.

I suspect that Kaibob might find his performance issues magically resolved if he were to install that Samsung internally in his Mini or attach it with a nice TB enclosure, run FSCK in recovery and enable TRIM.

I buy a lot of Samsung SSDs and have had no problems. Most recently I replaced the HDD in my wife's Acer notebook with an 850 Pro.
[doublepost=1497567778][/doublepost]

I go with "what works".
And that has worked for me, for almost five years now...

The key word here being me.

 

[mikeboss]

recently, german computer magazine c't published a test where they attempted to write SSDs to death. the SAMSUNG 850 Pro was the only survivor by the time they finished the test. I almost exclusively use SSDs from SAMSUNG (in my own systems and in the ones of all of my customers). I have had only one dead drive so far... oh, and BTW, the SSDs Apple is mounting in the iMacs, Mac Pros and MacBooks (Air and Pro up to 2015 models) are manufactured by SAMSUNG...

 

[JEREZANO]

sustained read is about 390 MB/Sec.
power on to login screen is about 15 Seconds.

mikeboss I got the lacie thunderbolt with 240 ssd but the boot speed is 27 sec do you think if I set trim enabler can be more faster like your 15 sec ?

 

[Weaselboy]

With the SSD's I used, I took benchmarks immediately after installing, and can compare them against benchmarks today (using BlackMagic's utility). The benchmark speeds remain the same.

If others here have empirical evidence that they can post that shows otherwise, then… post it.

https://forums.macrumors.com/threads/slow-ssd-write-speeds-on-older-imac.2053041/#post-24734082

Here is a recent thread you should read. This person has a Samsung 840 running without TRIM and write speeds had dropped to 25MBps. Just turning TRIM on brought the write speeds up to 150MBps. Then running fsck to TRIM unused blocks fully restored write speeds to 460MBps.

So there is your evidence. There are other threads showing exactly the same results.

 

[mikeboss]

mikeboss I got the lacie thunderbolt with 240 ssd but the boot speed is 27 sec do you think if I set trim enabler can be more faster like your 15 sec ?

you should enable TRIM in any case. bear in mind, that the time my system requires to boot is with a fresh install.

 

[mikeboss]

recently, german computer magazine c't published a test where they attempted to write SSDs to death. the SAMSUNG 850 Pro was the only survivor by the time they finished the test. I almost exclusively use SSDs from SAMSUNG (in my own systems and in the ones of all of my customers). I have had only one dead drive so far... oh, and BTW, the SSDs Apple is mounting in the iMacs, Mac Pros and MacBooks (Air and Pro up to 2015 models) are manufactured by SAMSUNG...

the SAMSUNG 850 Pro (250 GB capacity) tested by german computer magazine c't finally has died after 9.1 PB written.
that is 9.100.000 gigabytes which is roughly 60 times what SAMSUNG guarantees for this particular model!

 

[rkuo]

https://forums.macrumors.com/threads/slow-ssd-write-speeds-on-older-imac.2053041/#post-24734082

Here is a recent thread you should read. This person has a Samsung 840 running without TRIM and write speeds had dropped to 25MBps. Just turning TRIM on brought the write speeds up to 150MBps. Then running fsck to TRIM unused blocks fully restored write speeds to 460MBps.

So there is your evidence. There are other threads showing exactly the same results.

Samsung 840's specifically have a performance bug in the firmware that causes slowdown over time. They released several firmware updates to ameliorate the issue. I actually don't think they were ever able to fully fix it. Probably not a good reference point for this discussion.

http://www.anandtech.com/show/9196/samsung-releases-second-840-evo-fix

 

[Weaselboy]

Samsung 840's specifically have a performance bug in the firmware that causes slowdown over time. They released several firmware updates to ameliorate the issue. I actually don't think they were ever able to fully fix it. Probably not a good reference point for this discussion.

http://www.anandtech.com/show/9196/samsung-releases-second-840-evo-fix

The forum member in that thread says he had updated the firmware, but I get your point. This is just one example of many threads like that I have seen over the last couple years with all different brands. The user has write slowdowns, and enabling TRIM then an fsck run restores performance. It is not just something only related to this drive model.

As I recall, and it is mentioned in the article you linked, that bug was causing read slowdowns and was not impacting write speeds. The thread I referenced was primarily a write speed issue, so I do think the issue was TRIM related.

 

[rapicell]

I've used both USB 3 and Thunderbolt for both storage and boot drives. Personally I like thunderbolt more as I haven't had a single issue, with USB I had a few times where the drive wouldn't wake up properly and ended up having to restore it because it refuses to work, but I have a feeling part of the issues was the enclosure. The link below is the current drive I use for booting, it is small, but most of my storage is external while my internal drive I use for MacOS beta software testing. So far, the drive has delivered the expected speeds it list, so I've been pretty happy, tho I do have a 2012 iMac, so you can only get so fast anyways.

https://www.amazon.com/gp/product/B00RPVUDEU/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

 

[jmgrace]

OP:

TRIM is a NON-issue. Means nothing.
See this post I made yesterday for further detail:
https://forums.macrumors.com/posts/24676914/

Now that that's out of the way, let's get down to the issue of speeds.

USB3 (with an enclosure or USB3/SATA dock that supports UASP) will yield 430mbps reads, and 250-350mbps writes (the exact number will depend on the drive size, model, mfr.).

t-bolt2 would do little-to-no better, perhaps even worse.

Get a USB3 enclosure or USB3/SATA dock (or even an "adapter dongle") that supports UASP (USB attached SCSI protocol).
Then set it up and post back here with your experiences.
I predict you'll be VERY happy!

Getting a bit lost on all the conflicting info on the forums, so I thought I would ask: How do you guys feel about using an "off the shelf" SSD like the SanDisk 1TB Extreme Portable External SSD as a boot drive on a late iMac 2013 with USB3 (versus buying separate drives and enclosures)? Is there some tech reason to buy a separate enclosure I'm missing? Also, what is the best "step by step" link to follow to clone my current iMac 1TB HHD to this external drive and then set up the new external SSD as my boot drive to avoid supposed TRIM issues? (Also, Fishrrman thanks for all the great posts!)

 

[SaSaSushi]

Getting a bit lost on all the conflicting info on the forums, so I thought I would ask: How do you guys feel about using an "off the shelf" SSD like the SanDisk 1TB Extreme Portable External SSD as a boot drive on a late iMac 2013 with USB3 (versus buying separate drives and enclosures)? Is there some tech reason to buy a separate enclosure I'm missing? Also, what is the best "step by step" link to follow to clone my current iMac 1TB HHD to this external drive and then set up the new external SSD as my boot drive to avoid supposed TRIM issues? (Also, Fishrrman thanks for all the great posts!)

All the reasons for using a TRIM-capable drive have been posted to this forum so if you've read it in its entirety then you haven't missed anything. Because TRIM is not supported over USB there is no way to avoid TRIM issues with a USB-attached drive, although some users (such as the gentleman you thanked for his posts) will swear they haven't had any. Others in these forums, as previously mentioned and including yours truly, have had issues which they successfully resolved by enabling TRIM. Science and the phenomenon of write amplification would seem to support degradation of performance over time without TRIM. Garbage collection is not a replacement for it.

As for cloning, I think Fishrrman and I would both agree that the best tool for that job is Carbon Copy Cloner, although some in here also user SuperDuper.