Some help understanding M.2 and NVME

[MajorFoley]

So i plan on building a new rig soon, hopefully by the end of June which i will be using for 1080P 60fps content creation and streaming (when i get better net hopefully) and it kinda got me thinking about storage.

So i know M.2 is like Sata 6GB and they can have their own slots but what confuses me is the NVME part of it. When i look at motherboards like this

https://www.pccasegear.com/products/38096/asus-prime-b350-plus-motherboard

It says 1x M.2 Socket but would i know if it supports NVME? it has all these numbers on the specs storage sheet (which i can't copy/paste) like 2242/2260/2280 but i really don't know the difference between those

 

I was also taking a look at this video here

And its about 6 minutes 30 seconds in that he shows you the differences in pin and shows a motherboard connection and he mentions at one point a SATA M.2 can be put in a nvme slot although the m.2 has an extra hole for its connection and it kinda loses me here too.

Of course i may not end up getting a NVME or M.2 SSD and just get a bigger size Sata SSD but this is something i'd like to get a grasp on before i make a decision to purchase parts and would like to hear your opinions if i should get a SATA SSD, M.2 or NVME.

 

 

[agent_x007]

NVMe support is independent of MB's controllers/functions.
What counts is NVMe aware UEFI (or EFI booting), with GPT boot capable OS.
No other things are needed from MB point of view.
You may need drivers for your NVMe drive, but Windows 8 and newer have generic one inside.
Windows 7 SP1 has an update with it, which can be baked into installation - so no problems there.

As for M.2 standard and what can be used with it :
SATA or PCIe = Bus used
AHCI or NVMe = Interface used

You can have M.2 drive that support combinations of them :
1) SATA/AHCI
2) PCIe/AHCI
3) PCIe/NVMe
4) PCIe/AHCI + PCIe/NVMe
^This corresponds with notches on drive itself : 

M.2 "Key B" = SATA/AHCI
M.2 "Key B+M" = SATA*/PCI-e + AHCI/NVMe* (depending on drive)
M.2 "Key M" = PCIe + AHCI/NVMe (depending on drive).
A "Key M" drive is usually PCI-e x4.
A "Key M + B" drives are usually PCI-e x2 (but they can use SATA port).
*There are no SATA + NVMe "combo" drives (that would be stupid/impossible).

Side note :
Intel Optane drives are the only drives that can't work with SATA port or in AHCI PCI-e mode, while having "Key M+B" configuration.

[Technomancer__]

Quote

SATA is the market incumbent and dominant interface for connecting an SSD to the PC. It employs the command protocol AHCI (it also supports IDE) which was built with slower spinning disks in mind rather than flash memory. SATA transfer rates begin at 150 MB/s and max out at 600 MB/s for third generation technology. For most consumer uses of SSDs this is absolutely adequate.

 

Quote

NVMe is the latest high performance and optimized protocol which supersedes AHCI and compliments PCIe technology. It offers an optimised command and completion path for use with NVMe based storage. It was developed by a consortium of manufacturers specifically for SSDs to overcome the speed bottleneck imposed by the older SATA connection. It is akin to a more efficient language between storage device and PC: one message needs to be sent for a 4GB transfer instead of two, NVMe can handle 65,000 queues of data each with 65,000 commands, instead of one queue that with the capacity for 32 commands, and it only has seven major commands (read, write, flush etc). NVMe delivers better performance and reduced latency and is a scalable, but at a price! Take a look at Samsung’s offering of this technology in the 950 Pro to see how performance and price compares. This particular drive relies upon a new M.2 internal mount on the PC motherboard, as presumably will other future NVMe based SSDs. NVMe will also be the protocol of choice for the next generation of storage technologies such as 3D XPoint.

 

source: http://www.userbenchmark.com/Faq/What-s-the-difference-between-SATA-PCIe-and-NVMe/105

[captain_to_fire]

Someone is not watching Techquickie

 

[19_blackie_73]

the title of the video is misleading. as the others stated already, m.2 is a physical connector and sata and NVME are different protocols/standards. NVME can handle more throughput essentially, sata is limited by theoretically ~750MB per second, nvme allows for GB per second.

 

This particular board supports PCIe ssds, which basically means NVME ssds. Though as a normal user, I wouldn't bother at all about nvme and m.2 ssds in general unless you are working with very tight space and get a normal sata 2.5 inch drive. They are most times way cheaper and offer a very satisfying experience, you won't notice the difference to a nvme unless benchmarking.

 

2242/2260/2280 refers to the phyical dimensions btw. they are 22mm wide drives with a length of 42/60/80 mm respectively

[MajorFoley]

So to agent first:

So m.2 is jsut the physical connection on the MB i get that but the motherboard instructions like the one i links don't exactly sate if it's NVME compatibile just from the store page itself which is kinda what im asking, how can i tell if it supports it or not.

So if i say got the Samsung 960 Pro i could slug it into any M.2 slot go into the bios and change some option to PCI-E mode it would use the faster interface right? That is alot of information you listed and im a little confused on the combinations now, sorry if im slow on this but yeah even the notches part if i remember the video said something about the M.2 drives using B and M while the samsung pro uses just M isn't it?

Can you provide a couple of example drives?

 

Also just found that the numbers like 2280 are length dimensions of the card so thats that part out of the way as i found out but blackie also did post the answer here too so thanks for that. 

 

Huilun02 ok so on top of what agent said they are mainly just the way it interacts with the computer itself right?

 

Ethocreeper while that information is helpful doesn't kinda add to what im looking at here

 

And all of a sudden i think im about to call myself stupid and knock my head on the table.

Where it has the motherboard storage options I just noticed this damn line!

1x m.2 socket 3 with M key (so i assume it wouldnt fit a m.2 drive that uses B and M right?) type 2242/2260/2280/22110 storage devies support (Sata & PCIE 3.0 x4 mode)

Which i assume when any motherboard lists PCI 3.0 x4 mode it means that the motherboard can use NVME as well as Sata right?

 

 

 

[agent_x007]

No, you can't change PCIe/SATA buses "on the fly".
Bus type is "fixed" by the key on slot to which M.2 drive is plugged in. M-key slot = PCIe, B-key slot = SATA.
A "M+B key" drive, can be plugged in either M-key or B-key slot.
You can't use both at the same time, because there are no M+B keyed M.2 slots available on motherboards.

Yes, NVMe is compatible with your board.
Actually, NVMe is compatible with anything that uses EFI shell booting - example : LINK.

Drive examples : 
NVMe/AHCI M-key drive is Samsung SM950 (NVMe support depends on serial number).
NVMe only M-key drive, is for example Intel Optane memory.

As for booting :
With NVMe you don't get a drive to boot exactly.
NVMe booting requires EFI mode on installation and GPT partition system on the drive itself.
To actually boot from it, you have to set "Windows Boot Menager" as the boot drive in UEFI : LINK.
That option should come up once you install OS (or, at least, when most of it's files are copied on NVMe drive).

[MajorFoley]

17 hours ago, agent_x007 said:

No, you can't change PCIe/SATA buses "on the fly".

Isn't that option in bios i mean, for the nvme drive slot it has the option to set SATA or PCIE for that slot in particular.

Anyway looking here (https://en.wikipedia.org/wiki/M.2) is what kinda confuses me. Says if you get one with both notches you can plug into either slot. but if it was plugged into the slow with B you wouldn't be able to use PCIe speeds?

 

I think the guy mentions that some motherboards have 2 separate m.2 slots one for M key and one for B key i think...

 

And while it would be cool for a boot drive i would probably use a smaller SATA ssd like the samsung 850 evo for the boot and keep that one for the video editing.

Also surprised when i went to Samsung's website to look at the 960 pro it doesn't exactly say what key it is. I thought makers of these drives would kinda list it clearly instead of just saying m.2

[agent_x007]

7 hours ago, MajorFoley said:

Isn't that option in bios i mean, for the nvme drive slot it has the option to set SATA or PCIE for that slot in particular.

 

I think the guy mentions that some motherboards have 2 separate m.2 slots one for M key and one for B key i think...

You can change booting, but not the mode M.2 drives operates in
Think of it this way :
You can have double keyed devices.
BUT, there are no double keyed M.2 SLOTS you could plug them to.
M-Key slot = PCIe only.
B-key slot = SATA only.
 

Quote

Anyway looking here (https://en.wikipedia.org/wiki/M.2) is what kinda confuses me. Says if you get one with both notches you can plug into either slot. but if it was plugged into the slow with B you wouldn't be able to use PCIe speeds?

Yes.
If you plug B+M keyed M.2 drive into B-keyed M.2 slot, you may be limited by SATA speeds - that's true.
This kind of M.2 devices are hovewer limited to PCI-e x2 speeds regardless of what speed they actually are capable of (B-key "kills" additional x2 PCIe lanes to drive).
Also, keep in mind that not all B+M keyed devices will work in B-keyed slot.
Intel Optane is example of such device. 
 

Quote

...surprised when i went to Samsung's website to look at the 960 pro it doesn't exactly say what key it is. I thought makers of these drives would kinda list it clearly instead of just saying m.2

960 Pro :
NVMe drives can't work in "SATA mode" (ie. by using SATA cable to connect them to MB).
So by default, they are M-keyed devices only.
PCIe x4 lane speed in spec, also forces M-key only connector.