Using M.2 on Z97

[Guest]

So I have an Asus Z97-E motherboard which has an M.2 slot included. I'm still pretty new when it comes to motherboard features and bandwidth limitations. My question is, if I want to use an M.2 SSD, will it affect my available SATA or PCIe usage and if so by how much?

 

Thanks for your help!

[lx_srs]

So I have an Asus Z97-E motherboard which has an M.2 slot included. I'm still pretty new when it comes to motherboard features and bandwidth limitations. My question is, if I want to use an M.2 SSD, will it affect my available SATA or PCIe usage and if so by how much?

 

Thanks for your help!

It uses 4 PCIE lanes.

[TheKDub]

I believe it depends on the mobo, I'd suggest looking at your mobo's product page for info.

[Guest]

I believe it depends on the mobo, I'd suggest looking at your mobo's product page for info.

Found this on the spec sheet

*1: M.2 Socket 3 shares bandwidth with SATA Express port.

Talks about the PCIE slots but doesn't give a total number of supported lanes.

[TheKDub]

Found this on the spec sheet

*1: M.2 Socket 3 shares bandwidth with SATA Express port.

Talks about the PCIE slots but doesn't give a total number of supported lanes.

 

Then I'd guess that it runs off of SATA, and not PCIe.

[Guest]

Then I'd guess that it runs off of SATA, and not PCIe.

I got this off wikipedia:

SATA Express (abbreviated from Serial ATA Express and sometimes unofficially shortened to SATAe) is a computer bus interface that supports both Serial ATA (SATA) and PCI Express (PCIe) storage devices, initially standardized in the SATA 3.2 specification.^[1] The SATA Express connector used on the host side is backward compatible with the standard 3.5-inch SATA data connector,^[2] while it also provides two PCI Express lanes as a pure PCI Express connection to the storage device.^[3]

 

^{So I guess it's PCI Express in a round about way.}

[airdeano]

if you'll note in the devices .pdf, the list of M.2 drives are all SATA, not PCIe.

i fell into this as my Z97A will only except PCIe not SATA.

http://dlcdnet.asus.com/pub/ASUS/mb/LGA1150/Z97-E/Z97-E_Device_Report.pdf

[braneopbru]

if you'll note in the devices .pdf, the list of M.2 drives are all SATA, not PCIe.

i fell into this as my Z97A will only except PCIe not SATA.

http://dlcdnet.asus.com/pub/ASUS/mb/LGA1150/Z97-E/Z97-E_Device_Report.pdf

Actually, no.

 

The Plextor PX-G128M6e on that list is a PCIe SSD.

 

I learned all about the differences between SATA and PCIe SSDs that to my G1 Sniper board; turns out it only supports PCIe M.2 SSDs - which I learned after SATA one that I bought wouldn't work.

[ThomasD]

ASUS's documentation is a bit confusing.

 

The specifications page notes the m.2 slot of the Z97-E supports either SATA or PCIe, and that if you use a SATA m.2 drive it will share bandwidth on the SATA express port.  

 

http://www.asus.com/us/Motherboards/Z97E/specifications/

 

While the manual only talks about SATA operation, and does not address PCIe mode.

 

If a PCIe m.2 is used it will either run x4 or x2.  The M key standard supports up to x4 - but does not guarantee you'll get it.

 

Either way, those PCIe lanes are the same 16 lanes shared by your graphics card, so using a PCIe m.2 in that MoBo means your card will only run in x8  (not that you'll notice a difference.)  

[NumLock21]

z97 m.2 runs at x2.

[SkilledRebuilds]

z97 m.2 runs at x2.

This is the case for me..

However, I can use x4 and it will then disable Sataports. (Stated by my mobo bios description of the setting)

[braneopbru]

......Either way, those PCIe lanes are the same 16 lanes shared by your graphics card, so using a PCIe m.2 in that MoBo means your card will only run in x8  (not that you'll notice a difference.)  

 

Where did you read this? As far as I was aware, the SATA Express solution that Asus is using is running on the secondary PCIe 2.0 controller and thus would affect your PCIe 3.0 x16 slot.

 

Agreed though, ASUS' documentation is SHIT. I have a MSI board in one of my computers and right in the specs in the first couple of pages of the manual it says this:

 

 

- 1xPCI Express x16 slot, running at x4 (PCIEX4) * The M.2 socket shares bandwidth with the PCIEX4 slot. When the M.2 socket is populated, the PCIEX4 slot will operate at up to x2 mode.

 

At least this way I can make an informed decision about how I want to pick my hardware. 

[Guest]

I honestly thought I'd get a quick answer to this one, but it seems like a lot of people are just as confused as me when it comes to shared bandwidth on motherboards. This is probably not made easier by confusing documentation as a few of you pointed out. Is there a good YouTube video that explains this in detail? I've found some, but most of them like the techquickie just cover stupid things like you can use gen 1, 2 and 3 pcie interchangeably. This is something that has to be talked about more.

[NumLock21]

This is the case for me..

However, I can use x4 and it will then disable Sataports. (Stated by my mobo bios description of the setting)

What board do you have?

[SkilledRebuilds]

What board do you have?

Asus Z97-K - re-clarifying info.

 

This M.2 uses Sata ports afaik (may be able to use PCIE M.2, not sure) , and I also lose sata ports if I use the 2nd slot PCIE 2.0 4x instead of the 2x it is by default.

[NumLock21]

Asus Z97-K - re-clarifying info.

 

This M.2 uses Sata ports afaik (may be able to use PCIE M.2, not sure) , and I also lose sata ports if I use the 2nd slot PCIE 2.0 4x instead of the 2x it is by default.

According to your board the first x16 slot is 3.0 so basically it eats up all the lanes from your cpu. 2nd x16 slot is 2.0 so it's grabbing lanes off the Z97 chipset.  This 2nd x16 slot shares lanes from the 2 x1 slots, so if you set the mode to x4, then both x1 slots will get disabled. M.2 shares its lanes with SATA ports #5 and #6. All SATA ports grabs lanes from the chipset so basically the M.2 only runs at x2 and it supports both pcie or sata m.2 drives. When SATA ports 5 and 6 are being used then M.2 will be disabled. Rev 2.0 supports M.2 type 2242.

 

@adamjp

According to your board, the 2 x16 slots can do SLI at x8/x8 at 3.0 so basically that takes up all the lanes from your cpu. M.2 shares bandwidth with SATA Express. Both M.2 and SATA Express uses lanes from the Z97 chipset. The board will auto detect the type of drive your using and assign the lanes to that drive, so it's basically either m.2 or SATA Express. It does not say whether using one will disable the other, but my guess is, it might. So basically if you run a m.2 drive then both SATA ports on the SATA Express connector probably won't work. The M.2 on this board supports both PCIe and SATA protocols.