Can someone identify this m.2 port for me?

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updawg

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This is an MSI Cubi 2 - with a kaby lake processor and it looks like an m keyed m.2 slot but all the literature I can find says it is sata only. I thought sata is m+b keyed? Also are there m keyed sata only drives or would a m+b keyed sata drive work in this slot? And what is the length shown here?

Sorry for so many questions but when companies don't document and I'm not too familiar with m.2 type drives I don't want to make any wrong purchases.

Thanks!
 
https://commons.wikimedia.org/wiki/File:M2_Edge_Connector_Keying.svg to me it looks like an "M" keyed slot. Here's a SATA drive: https://www.bhphotovideo.com/images...ung_mz_n5e500bw_850_evo_500gb_m_2_1123190.jpg and here's an PCIe http://www.storagereview.com/images/StorageReview-Samsung-SM951-PCIe-SSD.jpg

When the host has more pins than the device plugged in, that's all good. The reverse is when things don't work. Ie. if the host would be B+M keyed and you tried to plug in the latter device then some pins on the SSD edge would find only air and it wouldn't work. In fact, while the above photo is a bit low res to clearly see, check this http://www.virten.net/wp-content/uploads/2015/09/NUC5i5MYHE-m2-ports.jpg to see the keying is actually supported by little plastic fingers so you are physically unable to plug in the module if it won't work. It's not just "I plugged in and it doesn't work" guesswork, that's for USB C, no, this is a sane standard where if you can plug it in then it'll work. It so happens that the image I just linked also shows clearly it's not B because B would be on the other side.
 
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This is Key-M but it is only a 22x42mm solution. That is a very unfortunate design decision on their part.
 
chx said:
https://commons.wikimedia.org/wiki/File:M2_Edge_Connector_Keying.svg to me it looks like an "M" keyed slot. Here's a SATA drive: https://www.bhphotovideo.com/images...ung_mz_n5e500bw_850_evo_500gb_m_2_1123190.jpg and here's an PCIe http://www.storagereview.com/images/StorageReview-Samsung-SM951-PCIe-SSD.jpg

When the host has more pins than the device plugged in, that's all good. The reverse is when things don't work. Ie. if the host would be B+M keyed and you tried to plug in the latter device then some pins on the SSD edge would find only air and it wouldn't work. In fact, while the above photo is a bit low res to clearly see, check this http://www.virten.net/wp-content/uploads/2015/09/NUC5i5MYHE-m2-ports.jpg to see the keying is actually supported by little plastic fingers so you are physically unable to plug in the module if it won't work. It's not just "I plugged in and it doesn't work" guesswork, that's for USB C, no, this is a sane standard where if you can plug it in then it'll work. It so happens that the image I just linked also shows clearly it's not B because B would be on the other side.
Click to expand...


Thanks for the info! A quick follow up is it possible to have a sata only m keyed slot? Or since more pins are present it has to support both?
 
In the picture I posted, look more closely at the M key socket. In the short section, it has 5 contacts on the top but 4 contacts on the bottom; the B key slot has 6 contacts on the top and 5 contacts on the bottom.

In the picture of a B key socket that chx posted a link to, you can see that the B key socket has 5 contacts on the bottom of the short section but you can't really see the top of the socket in the picture. In your picture, you can see that there are 4 contacts on the bottom of the short section of the socket but you can't really see the top section of the socket.

In this review of the Samsung SM951, there are pictures of both the front and back of the SSD; on the short section of the connector, you can see that there are 5 pins on one side and 4 pins on the other side. This way, not only is it unambiguous that it's an M Key, it's also unambiguous about which side would go up in your m.2 socket - if it could fit lengthwise, that is, which the SM951 will not since it is 80mm long. Kaos_Drem states your socket will only take a 42mm long SSD, presumably because he looked up the specs of the Cubi 2. Therefore, the thing you will need to watch out for is the length. The number you will need to be looking for when shopping for M-Key m.2 SSDs is 2242 (assuming Kaos-Drem is correct, I did not research that).
 
evilsofa said:
In the picture I posted, look more closely at the M key socket. In the short section, it has 5 contacts on the top but 4 contacts on the bottom; the B key slot has 6 contacts on the top and 5 contacts on the bottom.

In the picture of a B key socket that chx posted a link to, you can see that the B key socket has 5 contacts on the bottom of the short section but you can't really see the top of the socket in the picture. In your picture, you can see that there are 4 contacts on the bottom of the short section of the socket but you can't really see the top section of the socket.

In this review of the Samsung SM951, there are pictures of both the front and back of the SSD; on the short section of the connector, you can see that there are 5 pins on one side and 4 pins on the other side. This way, not only is it unambiguous that it's an M Key, it's also unambiguous about which side would go up in your m.2 socket - if it could fit lengthwise, that is, which the SM951 will not since it is 80mm long. Kaos_Drem states your socket will only take a 42mm long SSD, presumably because he looked up the specs of the Cubi 2. Therefore, the thing you will need to watch out for is the length. The number you will need to be looking for when shopping for M-Key m.2 SSDs is 2242 (assuming Kaos-Drem is correct, I did not research that).
Click to expand...

Thanks for the reply. However all m keyed ssds are pcie for purchase and none are 2242. The only 2242 are b+m keyed sata drives and I wanted to verify that worked.
 
updawg said:
Thanks for the reply. However all m keyed ssds are pcie for purchase and none are 2242. The only 2242 are b+m keyed sata drives and I wanted to verify that worked.
Click to expand...

Key M is backward compatible most of the time with Key B. it is not both ways though, key b will most of the time fit in key m, but key m drives will not fit in key b. I know its confusing...and m.2 is anything but simple lol, but sata based m.2 drives are key M+B most of the time.
 
updawg said:
Thanks for the info! A quick follow up is it possible to have a sata only m keyed slot? Or since more pins are present it has to support both?
Click to expand...

Let me repeat: this is not USB C where a socket tells you nothing what's supported (does it support USB 3.1 Gen 2 speed? DisplayPort Alternative Mode? HDMI Alternative Mode? Thunderbolt? Can you charge the device through it? Can it charge another device?). This is a sane standard. If it is not physically obstructed, it works. Therefore, since M keyed modules fit, PCIe x4, SATA and SMBus must be supported. The standard provides enough variation to manufacturers that they will provide sockets that are fully compliant.
 
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