SAMSUNG 950 PRO NVMe SSD 'unsafe shutdowns', NVMe driver, W10 x64 'unexpected shutdown'

@Fernando ,
I create this thread for W10 x64 boot media on SAMSUNG 950 PRO NVMe SSD user’s.
Samsung NVMe driver v1.4.7.17 is used.
SMART indication reports a non nul value of ‘unsafe shutdown’ counter for this device:

I ignore why this ‘319’ value for this counter, but if i compare to i750 SSD NVMe counter this one is nul:

The reason I observe this counter is to try to explain why I get on W10 x64 booting off 950 PRO an abnormal number of Windows ‘unexpected shutdown’ such as:

Is it a Samsung NVMe driver issue ?
Is it a 950 PRO controller firmware issue ?
Is it a W10 driver parameters issue somewhere ?
Is there any other reason ?

Booting off W10 from i750 NVMe I have never got any W10 ‘unexpected shutdown’ reliability message reported.

@100PIER :
Thanks for your report.

I don’t know the answers. Although my Samsung 950 Pro is running Win10 x64 as well, I have never seen an “unexpected shutdown”.
Nevertheless I have another and very bothersome problem with the Samsung 950 Pro: When I start my computer after having it powered off for some time (“cold boot”), the system always freezes at the beginning while showing the rotating circle. Powering off and repowering the computer solves the problem. So it seems, that it is an initialization issue of the Samsung 950 Pro SSD and maybe BIOS related.
Note: This “cold boot” problem does not occur, when I am using the Samsung SM951 NVMe or the Intel 750 as system drive. This verifies, that my problem is not caused by the NVMe driver.

@Fernando ,
Thanks for your analysis.

I understand that on your side the system (W10x64) SSD 950 PRO S.M.A.R.T. ’ unsafe shutdown ’ counter value is absolutely = ZERO ?
And on your side is it true whatever the machine (and BIOS) the 950 PRO is plugged in ?

I have to check and observe carefully on 2 different systems I have (Z77 and X99) using each one a 950 PRO this ’ unsafe shutdown ’ parameter value evolution…

It is very strange that Magician v4.7 never warms on this parameter value … which seems specific to NVMe devices.
I ignore the exact reason and signification of this smart parameter not described in the public 950 PRO documentations.

I share with you the idea the “cold start” problem is a potential BIOS issue.
On my side I observe that “shutdown” i750 (OS system) takes sometimes several tens of second up to 5 minutes (‘round circle’).
A contrario shutdown 950 PRO (OS system) takes never more 1 or 2 seconds on X99 and about 4 seconds on Z77 !

Do you have observed on your side a similar (strange) thing about shutdown time difference (i750 vs 950 system) ?
If shutdowning is very very short why not initialization problem detected for the next repowering, and why not ‘unsafe shutdown’ logged in SMART value parameter ?

No, I haven’t yet even checked the “Samsung 950 Pro S.M.A.R.T. unsafe shutdown counter”. How can I get these informations?

Since my Z97 system is currently using the Samsung SM951 NVMe SSD as system drive, I just have installed and run the tool HWInfo64.
This is what the tool shows regarding “unsafe shutdowns”:

Unsafe shutdowns Samsung SM951 NVMe.png

The tool obviously counts the “unsafe shutdowns” of the complete SSD’s lifespan: The currently running OS has been freshly installed last wednesday (06/22/2016), but the listed “Power On Hours” are 559 hours.
As far as I remember, I had a lot of freezings in the past while trying to run Samsung’s Magician resp. the benchmark tool named SSD-Z. So I don’t think, that the listed “unsafe shutdowns” have been caused by the SSD itself.

Off topic:

You are writing within this thread about a Samsung SM950 Pro SSD, which doesn’t exist and may be mixed by the readers with Samsung’s SM951 SSD. The correct name of the SSD is 950 Pro (without “SM” before the “950”). To avoid any misunderstandings you should correct the SSD name within the thread title and your start post.

@Fernando ,
Thanks for the correct Samsung 950 PRO proper naming. I have fixed it in this thread.
You can get the Samsung 950 Pro S.M.A.R.T. values using diffrent tools such as HWINFO64, SIVx64, Magician, Speccy, etc…
I have tested SSD-Z tool but had some troubles with whatever the SSD used and the platform used and so abandonned this tool.
Here is Magician screen:


I note you get also ‘unsafe shutdowns’ non zero value with SM951 NVMe !
Please, can you have a look on your Samsung 950 PRO and on your i750 what are the values ?

@100PIER :
Off topic:

Please stop inserting all screenshots by using an extra large size (unless it is really useful). The users want to get easy to read informations and not pages full of enlarged pictures (which may even be quoted by others).
It takes me always an extra time to edit your posts and to resize the screenshots.

After having gotten a lot of BSODs while starting Samsung’s Magician, I have abandoned this tool as well. In my eyes this tool is crap and only useful for people, who want to get extremely high benchmark scores by running the RAPID mode (which measures the DRAM speed, but doesn’t improve the real SSD performance at all).

As soon as I have the required time, l will do that.

Meanwhile I have temporarily replaced my currently in-use Samsung SM951 NVMe as system drive by the Intel 750 NVMe SSD. Both are running Win10 x64 Insider Preview Builds.
This is what the tool HWInfo64 shows regarding the "Unsafe Shutdowns":

Unsafe Shutdowns Intel 750 SSD.png

As you can see after clicking onto the screenshot, the tool encountered at least 17 “Unsafe Shutdowns” on my Intel 750 SSD.
This verifies, that even the Intel 750 SSD is not safe regarding unexpected shutdowns.
My conclusion:
The “Unsafe Shutdowns”, which are listed by some hardware diagnostic tools, are not caused by the related SSD, but by something else.

@100PIER :
I suspect, that your “Unsafe Shutdown” result “0” while using the Intel 750 SSD is caused by the fact, that you didn’t yet run Samsung’s Magician with this SSD (wouldn’t make much sense, because the SSD is not manufactured by Samsung).

@Fernando ,

On my side I use Intel SSD Tool and Samsung Magician Tool on the same W10 x64 system because my platform X99 has the both SSD Manufacturers up and running (see my signature).

I observe for i750 , 1523 hours powered on, ‘unsafe shutdowns’ = ZERO.
I observe for 950 PRO, 817 hours powered on, ‘unsafe shutdowns’ = 319.
I observe Intel SSD tools v3.3.6 does not display the ‘unsafe shutdowns’ “0D” parameter, however Magician v4.7 does.

I report the HWinfo64 screens:



and DiskInfo screens:



If somebody can explain why does ‘unsafe shutdowns’ specific to NVMe devices does represent, it may be helpful.

(Nota: On my SM951 SSD AHCI device the ‘unsafe shutdowns’ parameter does not exist)

It seems, that such data are not stored by “normal” (non-NVMe) SSDs.
Hardware diagnostic tools like HWInfo or Samsung’s Magician can only read data, which are present somewhere.

@Fernando ,
Here is the description of what the ‘unsafe shutdowns’ counts for SSD NVMe devices.
This information is extracted from Intel SSD Tool Help, however current Intel SSD Tool v3.3.6 does not display this count.


Hello guys, thought I would share what I see as well. Here too, Samsung 950 Pro 512GB. I am using HD Sentinel and mine shows something similar. I work from home so I know if my system would have had one. On 6-8-2016 starts the climb to where it is today. I checked my logs and I cannot find any activity of driver updates or Microsoft updates in or around 6-8. I wish I can go back in time to see when the first 8 appeared. I do know I installed the Samsung NVMe driver on 3-9-2016 per my records and I built this system on 12-5-2015 using the older driver version till March. Looking at HD Sentinel then that means I had 8 unsafe shutdowns even with the older driver.

Using Asus Maximus VIII Hero

Anyways just sharing what I am seeing thanks to both of you bringing this up.


Yes, that is what I have expected. It just counts these events, but says nothing about the reasons.
I bet, that not a single “unsafe shutdown” has been caused by the SSD itself.
By the way: I know the most often reason of the “unsafe shutdowns”, which are counted by my Samsung SSDs. It were the freezings, when I tried to install and run Samsung’s Magician. That is why I avoid this tool now.
When you get a BSOD or a freezing of your system, you have to push the power button with the consequence, that the SSD counts an “unsafe shutdown”.
During the last years I had a lot of them, because I am not a “normal” PC user, but someone , who tests a lot of different hardware configurations and system tools.

@Fernando ,

I have uninstalled now Magician on all my PCs and will observe if ‘unsafe shutdowns’ becomes stabilized or not.

On my side it is very very rare I got a BSOD and have to stop the PC, so I don’t explain why I have 319 ‘unsafe shutdowns’ events.

I observe that on 2 different PC’s with a Samsung 950 PRO installed I see logged in Window Reliability panel abnormal (randomly) ‘Unexpected Windows shutdown’ critical errors (may be 3 or 5 times per day).

The question is:
Does Samsung 950 PRO ‘unsafe shutdowns’ events and W10 ‘Unexpected Windows shutdown’ error are correlate or not ?

I observe on my PC booting off i750 I have never got any W10 ‘Unexpected Windows shutdown’ critical error (1530 Power On Hours) !
No ‘unsafe shutdowns’ and No ‘Unexpected Windows shutdown’.

On my side, I bet for a Samsung NVMe driver malfunction.

Both mean the same event, but the SSD registers each "unusual" shutdown of the related SSD (e.g. by unplugging it), whereas Windows may only register an unusual shutdown of the system drive.

I was looking at my HD Sentinel report again and something strange. That error date 6-28-2016, I woke up today and started the computer and it has never shut off. I have been working on the system this whole time (3 hours before I saw this post). I know for sure no shutdown occurred

I checked another system with the same 950, it too shows 7, but there is no spike like mine today. Just a straight line and that one did not record a spike today when I turned that on. (Checked again after 2 hours and still at 7)

I also checked both systems in the Windows reliability and no entries. I am pegged on 10 in the graph so I am not having your issue 100PIER nor Fernando’s with the pause at boot up. Maybe if the reading gets worst it will for my systems. Only time will tell.

@100PIER - I think I am going to do what you are doing; uninstalling Samsung’s Magician and just go with what HD Sentinel will report going forward. I’ll try to update later on with my numbers too

I observe when using Samsung 950 PRO as system drive, Windows registers ‘unexpected shutdown’ time stamped events and Samsung 950 PRO registers ‘unsafe shutdowns’ non time stamped events.
So, I agree it is difficult to correlate these events.
May be the source of the problem is when I am asking to shutdown the PC system via the Windows panel control and if for any reason the shutdown process is an excessive time long (may be due to any software conflicting buggy applications) an automatic Windows ‘time-out’ process occurs somewhere and this ‘time-out’ is logged as an ‘unexpected shutdown’ event by Windows.
May be in that case Windows stops abruptly SSD 950 PRO which registers an ‘unsafe shutdowns’ event.
For me this cascade of all these events is possible but it is strange that when using the i750 SSD system drive no such ‘events’ are observed.
May be ‘abrupt stop’ is less ‘clean’ for 950 PRO than for i750. (it depends of driver/controller/firmware/bios).

Yes, this is a possible explanation for the registered "unexpected shutdowns".

Or it is just mere chance, that your Intel 750 (contrary to mine) has not yet been affected by an "unexpected shutdown".
Both options seem possible for me.

@100PIER :
Here is the requested HWInfo64 screenshot showing the amount of "unsafe shutdowns" of my Samsung 950 Pro SSD, which is currently running Win10 x64 Insider Preview Build 14376:

Unsafe Shutdowns Samsung 950 Pro.png

So I can confirm, that my Samsung 950 Pro had much more "unsafe shutdowns" than my other NVMe SSDs.

Maybe an interesting observation:
Directly after the clean install of the OS onto the Samsung 950 Pro the HWInfo64 tool showed 82 "unsafe shutdowns" of the SSD.
After having powered off the computer for 30 minutes I tried to restart the computer and got my wellknown "Samsung 950 Pro coldboot freezing".
A simple reboot was successful (as always) and now HWInfo64 showed 83 unsafe shutdowns. This verifies, that all my freezings I had in the past with my Samsung 950 Pro and the following reboot were counted by the SSD as "unsafe shutdowns".
I think, that it is the initialization of the SSD and not the SSD itself, which is faulty. If I am right, an optimized NVMe BIOS module may solve the problem.

@Fernando ,
Many thanks for your data analysis.
I agree that a problem is with Samsung NVMe BIOS module or may be Samsung NVMe driver itself.

For i750 does an ‘Intel NVMe BIOS’ exist ?

You are lucky to have only “83” ‘unsafe shutdowns’, it is 4 times less than on my 950 PRO device, but i see you have 8 times less than me on ‘Power On Hours’.
So, it is sure that a proportianility rule does exist with ‘Power On Hours’ and ‘unsafe shutdowns’ and that problem does exist from the beginning of the product.

For me it is a ‘misconception’ of Samsung pieces of firmware/Bios NVMe, not the 950 PRO by himself, and we discover this “side effect” after some hours of usage and also we can compare , in the time, with other SSD NVMe manufacturer’s solutions.

On my side, i don’t understand the huge value of ‘unsafe shutdowns’ because I have observed only 1 or 2 ‘freezings’, no more, from the time I have plugged in this device in a system.
‘freezing’ is not the unique explanation of the ‘unsafe shutdowns’.

Since I wanted to know the reason for my “cold boot freezings” while using the Samsung 850 Pro SSD, I have recently done some tests by changing the NVMe driver and the NVMe BIOS module.
This is what I did:

  1. At first I flashed a BIOS, where I had replaced the original EFI module named “Nvme” module by a newer “Nvme” version, which I had extracted from an ASRock Z170 Extreme7 BIOS. After having restored my previous BIOS settings I tried to do a “cold boot” into my Samsung 850 Pro running Win10 x64 Build 14376.
    Result: Nothing had been changed. I got my wellknown freezing.
  2. As next step I replaced the “Nvme” module of my mainboard’s BIOS by the “NvmExpressDxe” module, which had been built by the Clover Team and SoniX.
    Result: Again no change. The cold boot freezing appeared again.
  3. After having reflashed the BIOS with the original “Nvme” module, I replaced Samsung’s NVMe driver v1.4.7.17 by the latest Win10 in-box MS NVMe driver named stornvme.sys v10.0.14376.0.
    Result: Until now I have done 3 cold boot procedures and didn’t get any freezing (previously I got them at each cold booting).
    By the way: The OS booted much faster than with Samsung’s NVMe driver. I didn’t even see a rotating circle while booting.

My conclusion:
According to my test results it is Samsung’s NVMe driver v1.4.7.17, which seems to be responsable for my cold boot problems while using the Samsung 950 Pro as system drive (Note: The Samsung SM951 NVMe is not affected by this issue!).
To verify this intermediate result, I will let the current configuration run for a while and then do a look to the “unsafe shutdowns”, which are listed by HWInfo64. Currently the tool has counted 85 of these events.