Z170 Extreme 4 + Samsung 950 Pro = :( SOLVED!!!

Sorry 'bout that....my board is horizontal.
Mounted on a caseless benchin' rig 

Sata 3 -0 and 3    -1 are indeed horizontal.
View image on page 25

I apologize for that. Understand my annoyance on the problem I'm having, though...


Here's the same image without any words :)




Could this be the root of the issue, perhaps?


Edited by EvilDragon - 23 Jul 2016 at 11:17pm

BTW here's a screenshot of System Info for Windows about temps... I think I have a pretty cool machine :)

EvilDragon wrote: Unfortunately no change! :( Magician still reports 8 Gbps and benchmarks are the same...

Oh I thought I nailed that one! Sorry to hear that!

I still think it is suspicious that your benchmark results look like a SATA III SSD. Now that I looked at it again (the Crystal results in particular), the results for the 4K and 4K Q32 are bad even for a SATA III SSD. The high queue depth (Q32) performance of NVMe SSDs is far superior to SATA III SSDs, which we are not seeing in your benchmarks. It is very strange that the Sequential Q32 Read speed is less than half the single file Sequential speed, 525MBs vs 1218 MBs.

This is my 256GB 950 Pro on my ASRock Z170 board. Apparently you've never had a result like this:



This is a Samsung 840 Pro in the same PC:



Here's another thing I just noticed. I updated to the latest version of Magician, and got this:



It shows 8Gbps now for my Z170 board's M.2 slot too. I ran Crystal again on my 950, and the result was normal.

After checking into this, I learned that DMI 3.0 and PCIe 3.0 are both rated at 8Gbps (or more accurately, 8GTs, 8 Giga-Transfers per second). So the Magician software is now reporting the DMI 3.0 speed correctly. The 10Gbps rate is actually what a DMI 1.0 x4 connection would provide. This is unrelated to your problem.

I wonder how correct this data in Magician really is. Meaning is it truly checking the connection bandwidth and width provided to the 950 Pro.

Moving on, my thoughts and suggestions for you:

Have you ever checked the temperature of the 950 Pro? They run hot, and will throttle their speed at ~70° C. It seems you have nothing covering it, your three cards in the PCIe slots are all below it, and you don't have a video card. What do you use for a CPU cooler? What kind of PC case do you have, and location of case fans?

The monitoring programs HWiNFO64 and AIDA64 will display the temperature of your 950 Pro. When I just ran Crystal on my 950 Pro, it reached 54° C. The temperature throttling is a known issue with this SSD, it has been found and reported in many reviews on the Internet. I have a small heat sink on the controller chip, and a fan blowing air over the mother board in that area, so it idles at 34° C, on a warm day like today. The Magician SMART data for the 950 Pro has temperature data, but it is not converted into a true value.

I wonder if you have a defective 950 Pro? Have you ever had a benchmark result better than the one you posted?

I would remove the 950 from the M.2 slot, but first I would check if it was inserted in the M.2 slot correctly. You have it mounted with that tiny screw, right?

Remove it (carefully) and examine the M.2 slot itself. Do all the tiny connections seem fine? All lined up evenly, none shorted together or damaged?

Check both sides of the 950's connection end. You could clean the gold contacts with alcohol on a Q-Tip, and if you have that compressed gas for blowing off dust, do a few short bursts (NOT TO CLOSE!!) at the M.2 slot. Looking at the M.2 slot on any board, it's a miracle they work IMO.

Have you tried clearing the UEFI/BIOS? If not, save your current settings in a profile first, and then shutdown the PC, remove it from power, and do a full UEFI/BIOS clear. That is, move the CMOS jumper to the clear position, and remove the board's battery for several minutes. You probably can skip removing the battery, but I would definitely try a UEFI clear.

I can't think of any other UEFI options that would cause this issue. I have those DMI ASPM options enabled in my UEFI configuration, which is not causing any problems.

I would leave Force M.2 on Auto. You are positive you don't have a SATA drive connected to the SATA3_0 or SATA3_1? The numbering of the SATA ports can be confusing, those two ports are next to each other vertically, not horizontally.

Did you check the Device Manager entry for the Samsung NVMe controller? Seems fine in Magician, but who knows?

Did you ever run a manual TRIM on it, in Windows, the Properties, Tools, Optimize option? I wonder if the multiple OS installations has it in need of cleanup.

This is a weird but fascinating issue. I was hoping changing Force M.2 would work, but did not want to find a bug in the UEFI, which that would be. Please check your 950's temperature first, then do the UEFI/BIOS clear test, and finally the physical removal and inspection.

I really want to keep after this one, so let me know!