Interesting observations with the PM951 512GB SSD

So I purchased a buddy's i7 9550 with a 512GB PM951 drive and have been having a heck of a time with it. If it is in ACHI mode it will not reboot (can't find the harddrive), on bios 1.1.15, but that's another issue.
Here are my AS-SSD results below.

First I did a fresh install with ACHI enabled:

As you can see I stopped the test because it was going to take too long. My 4k write speeds were .7MB/s (yes 7/10ths)...

Then I put the RST drivers on to see if that would help:

Same issue sadly, but my reads were better...

For fun I put on the Samsung NVMe driver:

Much better results.

Then I did a fresh install in raid mode and got this:

Installing the RST drivers made no difference.

I didn't have any of these issues with my i5 version and my 950pro (no reboot issues, no speed issues, nothing). Bummer dell can't figure out their bios to fix the "phantom" drive. I believe they fixed it on the 9350, why can't they figure it out for us.

 

when I reinstalled windows with a legacy boot usb drive I could boot on UEFI because the hard drive message but I think I didn't have this problem. I reinstalled windows using Rufus and I can boot from UEFI with RST driver. I'm getting 1900 read and 1000 write
EDIT: RAID here

 

Have you ran AS-SSD to see what your 4k speeds are like?

 

I'm using Crystalmark
edit: okay I'm seeing very different results on AS SSD. VERY DIFFERENT! I think I will thrust on Crystalmark

 

Do you mind posting your crystal mark?

I think it's weird that with the NVMe driver AS-SSD runs fine but with the others it does not.

 

Im going out for lunch now. But i left my XPS setting up for AHCI, im going to try what you did.
I will post the crystal results later. But I got on AS SSD 200 of write on sequential and on crystal I got 950-980

 

Cool, let me know, thanks!

 

here!
http://imgur.com/qta34gy

 

Humm interesting results. One weird thing is my 4k read/writes (non q32) are 100mb/s faster on mine than yours when I run crystal mark. I should have ran it in raid mode...

 

Looks like it doesn't like to reboot on AHCI mode. I have to shut down and turn it on to "reboot"
Aaaand no hard drive hahaha
Man raid was great.
EDIT:
Tests results
http://m.imgur.com/NN22Q1v,Xxcja6P

 

Yeah your 4k results are more in line with what my 512gb does there. Did you try AS-SSD while in ACHI mode? I also have the reboot issue, I am trying to chat with dell tech support to see when/if a bios update will be released to fix it.

 

These results are on ACHI mode with Samsung NVMe driver

 

Yeah sorry I meant AS-SSD, not crystal mark...

 

What? When I was on RAID the AS SSD 4K was 0,7MB and the sequentials were pretty bad. Now on ACHI I'm getting the results of the pics

 

LMAO, sorry I didn't scroll down to see that you had two pictures there. That's my bad...

 

lol no problem!

 

sitting in chat with dell tech support, they aren't very helpful...

 

I'm trying here too. waiting...

 

This is beyond painful. Dell must think everyone that contacts tech support is a total moron.

 

Well after an hour of the tech telling me just to go back to raid mode and not worry about the performance hit, I have finally talked him into sending Tier 2 an email. I doubt anything will come of it, but who knows.

 

I got then saying that they are aware of this problem but the system is made to work with RAID no ACHI, but they are trying to fix it. And the BIOS not showing the correct version, they made a reflash, and it didn't work ( no surprise here)

 

Lol right, they say the system is made to work in raid mode because that's the only way it happens to work. I have no issues with my i5 and the 950 pro in ACHI mode...

 

Man I wish they made a 1Tb 950 pro and I wish I had money to buy a Razer Core with a 980Ti or a Pascal GPU

 

Lol I know the feeling. I am tempted to buy a 512gb 950 pro just to be able to reboot.... I do however have a 980TI in my desktop hooked to my Dell 34" monitor to make me forget my tribulations...

 

I don't know why people are still using AS-SSD to make these "interesting observations" when that tool is clearly broken in its current form. CrystalDiskMark gives accurate readings, and FWIW shows near identical performance in both RAID and AHCI modes. There are plenty of posts elsewhere here as evidence of that.

 

Lmao, so please do me a favor and show me evidence that AS SSD is broken. Also, why does AS-SSD work on every SSD I've ever tested it on (been a tech for 14 years prior to going to medical school, I've tested a fair share of SSDs). Not to mention it has the same issue with AHCI or RAID without NVMe drivers. I noticed a bit of lag when I first installed windows with AHCI. Not to mention that Marcelosiciliano's 4k performance in Crystal Mark went up by 100mb/s in AHCI mode...

Regardless of your opinion of AS SSD, Dell should figure out how to properly implement AHCI in this laptop...

 

You really think a 4K speed of < 1MB/s wouldn't be immediately noticeable in everyday use? Yes, it's broken for this particular driver/hardware combo.

 

just to add: reviews of the 951 on Anandtech and PC Gamer, with their benchmarks.

http://www.anandtech.com/show/8979/samsung-sm951-512-gb-review

- Unfortunately, Samsung changed its initial plans and the SM951 as it's known today does not support NVMe
- It's likely that Samsung's PC OEM partners wanted to stick with known AHCI command set for improved compatibility
- Despite the lack of NVMe, there's no arguing about the fact that the SM951 is the fastest client SSD and by a very healthy margin.


http://www.pcgamer.com/samsung-sm951-m2-ssd-review/

- The SM951 is not just faster than the 850 EVO. It’s faster than three 850 EVOs at once
- Several motherboards tested with the SM951 didn’t recognize it at all, and a few that did refused to use it as a boot device. BIOS updates resolved some of these issues, but compatibility remains troublesome.
- Whether the Samsung SM951 is worth the money comes down to whether your hardware has what it takes to recognize and run it properly. You’ll need a recent BIOS, a full speed M.2 slot and a little bit of luck.

 

Sadly we get stuck with the PM951, not the SM951, totally different ball game...

 

Thanks for that full proof evidence, how can anyone argue with that.

I did notice lag when I was copying over user data (25k small files). I've probably tested 25 different SSDs with AS SSD and this is the first to exhibit anything remotely similar to this. The fact that it's cleared up by the NVMe driver (all the while crystal mark gets an extra 20% boost), I think there's an issue with the dell setup.

 

wow, i'm totally out of it! thx for the heads up.

 

Did the new BIOS fixed the reboot issue?

 

Sadly no. Still tempted to buy a 950 pro, lol.

 

I have random lags in Windows transisiton animations, very bad on battery. Is that the problem as highlighted by as-ssd

 

Unlikely. Plenty of people have the AS-SSD thing, without any lags in the animations

 

https://downloadcenter.intel.com/download/25165/Intel-Rapid-Storage-Technology-Intel-RST-RAID-Driver
You should try this. And AsSSD results in RAID mode will be solved.

 

Interesting. I did try 14.8.0.1042 and it did not help, I may try it again. Which SSD is that?

 

Samsung PM951 256gb from XPS 9350.

 

Cool thanks for the info, I'll give it another shot.

 

Man! No hard drive on AHCI reboot is fixed for me. Using Samsung NVMe drivers

 

Interesting, did you change anything? I installed the bios and hit restart and it didn't restart, lol...

 

Well I'll be darned. I reapplied the bios update and the restart issue is gone. Dell did something, I'm amazed!

 

scared to run the BIOS update ... so many inconsistencies with DELL software.

but tempted

 

I don't know of any downsides to running the bios update. It's like it just didn't take the first time, not sure why. My battery life seems to be the same, and my machine reboots!

 

Noticed that while using AHCI the 4K speeds get worst every time that the computer sleeps and it can get to pretty unusable levels

 

Is that normal sleep or hybernation? I haven't noticed it, but I use my desktop most of the time I'm not in school.

 

Man this SSD speeds are making me crazy. I just cant get 4K speeds like they should be!!! I'm trying everything! Using AHCI RAID. After a reboot or a sleep me 4K are 300mb and they were 600. Just cant fix it!!

 

made the plunge, took on the first try ... and reboot bug is gone!

(fwiw: AHCI, IntelRST, i7/16/951)