@centaurium :
I am not sure, whether any PCIe>M.2 adapter will use more PCIe lanes than an M.2 connected SSD natively does.
It depends on the manufacturer and the model of the mainboard, but I am pretty sure, that it will work.
Hi!
Thank you for encouraging information! I have SM951 256Gb AHCI with adapter M.2-> PCI-ex and LGA771 mobo Supermicro X7DWU with Phoenix BIOS. This BIOS has an option “EFI OS Boot (If enabled, this feature provides support for EFI OS booting. The options are Enabled and Disabled.)”. Is it possible to insert SAMSUNG_M2_DXE.ffs file into this bios ?
Thank you!
@kokos76 :
Welcome at Win-RAID Forum!
Yes, but the question is, whether it works or not.
You will probably have to find it out yourself.
Good luck!
Dieter (alias Fernando)
is there a work-around that allows OS booting from PCIE SSD on any s1366 PC - I have a Samsung XP941 in a dual socket Xeon rig. Would very much like to boot from it!
When I install windows, windows recognises it but does not allow installation to it as it somehow knows my BIOS/pc will not boot from it 
TIA!
@ae00711 :
Since your request has nothing to do with the storage drivers of your Operating System, but with the mainboard BIOS of your system, I have moved your post into this already existing thread.
Now to your problem:
I doubt, that you will be able to boot off your Samsung XP941 SSD, because your X58 chipset mainboard doesn’t support any EFI module.
AFAIK the Samsung 950 Pro SSD is the only M.2/PCIe connected SSD, which may be bootable with your LEGACY (non-UEFI) mainboard, because the related SSD chip contains the required LEGACY mode Option ROM.
thank you so much! I am admittedly a bit of a n00b! 
rats! 
thanks for the help/answers, much appreciated! 
Hello guys!
After 3 days of searching and frustration I just finished installing SM951 AHCI model and making it bootable. I want to thank Fernando and all people who contributed to this forum. I confirm that guide in this thread 100% works on system:
ASUS P9X79
Samsung SM951 512GB M.2 AHCI (Lenovo model)
Cheap M.2->PCIE adapter
Regards.
@kamokar :
Welcome at Win-RAID Forum and thanks for your feedback!
Enjoy your fast Samsung SM951 AHCI as system drive!
Dieter (alias Fernando)
@Fernando ,
Is, at this date, Microsoft W10 x64 AHCI SATA standard driver (native W10 in the box) the only way to drive a Samsung SM951 AHCI SSD on a performant platform ?
Currently I use it and it works, but if any other solution does exist I am ready to test it.
@100PIER :
AFAIK there is no alternative driver available for M.2/PCIe connected SSDs, which are using the AHCI protocol.
As soon as Samsung or any other SSD manufacturer will release an AHCI driver for these SSDs, I will offer them within the start post of >this< thread.
@kamokar :
Hi,
Can you describe what did you do in order to get it running?
I purchased a HP Z Turbo Drive G2 that has SM951 installed.
It is not visible in my system in BIOS nor in Windows
I was trying to mod my BIOS with NVM modules but it does not work
I have ASUS P9X79WS MOBO with Intel i7-4930K CPU.
What M.2/PCIE Adapter do you use?
Regards,
Sebastian
EDIT by Fernando: This post may be misleading, because the user kamokar reported about the AHCI variant of the SM951, whereas the author of this post obviously has a Samsung SM951, which supports the NVMe protocol.
so basically i can plug this
http://www.amazon.com/Samsung-850-EVO-3-…W/dp/B00TGIVY1G
into this
http://www.amazon.com/Sedna-Express-Adap…t/dp/B00XU7N0JS
on this
https://www.asus.com/Motherboards/H81GAMER/overview/
(yep…i already got an 850 M.2 looking like a useless laptop wifi card right now )
EDIT by Fernando: Unneeded blank lines removed (to save space and to improve the readability)
@agablex :
Welcome at Win-RAID Forum!
Although only a user with a similar hardware configuration can give you a definitive answer, I think, that your project will end with a success.
What I do not see is the relationship between your plan and the topic of this thread: The Samsung 850 EVO M.2 SSD supports the AHCI and not the NVMe protocol.
Regards
Dieter (alias Fernando)
well does that mean my bios will recognize the M.2 drive through the pci adapter as a boot drive without the rom injecting ?
edit: never mind i got it
https://www.youtube.com/watch?v=gABlQz0ktd0
@agablex :
Maybe you will have to insert a special BIOS module to get the AHCI supporting Samsung M.2 SSD bootable. For details please look into >this< thread.
The insertion of an NVMe supporting BIOS module is useless, because your desired SSD does not support the NVMe protocol.
1) that’s more like it i’ll check that out
2 )yes exactly
thanks a lot you’ve been a big help
@agablex :
Since you had posted your request into the wrong thread, I have moved our discussion into the correct one.
@Fernando
Thanks for the information that you posted on here, I was able to get a SM951 (AHCI varient) to boot with a ASUS Maximus VI Hero, via a ASUS Hyper M.2 x4 Mini PCIe Kit.
I followed your instruction >here< to create a MOD BIOS, based on the latest BIOS for Maximus Hero VI build 1603, and inserted the “SAMSUNG_M2_DXE” module provided >here< by our Forum member xelanaiznac.
To flash the motherboard with this MOD BIOS, I also had to do the Asus BIOS Flashback method, basically updating the BIOS with a USB drive via the designated USB Port on the back. The MOD BIOS had to be renamed to “M6H.CAP” for this to work as well. Instruction provided by Fernando >here<
Without the MOD BIOS, SM951 would not show up under UEFI/BIOS; I was only able to access the SM951 SSD under Windows 10. Only after flashing the Maximus VI Hero with the MOD BIOS that I was able to see SM951 being listed in Boot Menu under UEFI/BIOS, which allows me to set it as the main boot drive.
@babubulala :
Welcome at Win-RAID Forum and thanks for your feedback!
I am glad, that you succeeded by following my guide.
Enjoy your Samsung SM951 AHCI as bootable system drive!
Dieter (alias Fernando)
@Fernando ,
Thank you for your guide and all the information you provided to fix my Bios. I finally succeeded to boot on my SM951 AHCI (was initially only recognized by OS, not BIOS). The “SAMSUNG_M2_DXE” module did nothing with my Aptio V. Maybe because of the NVMe EFI modules already there (nvme, nvmeint13, nvmesmm), my laptop had a PM951 NVMe at first. So the only way for me had to add the “pciesatacontroller” module with MMTool to get the AHCI boot, I found it here (seems to be a standard module as this is from desktop mainboard).