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What other connectors are coming down the pipeline or may currently be in draft specification phase? Admittedly, I totally did not know NVMe’s were becoming a

What other connectors are coming down the pipeline or may currently be in draft specification phase? Admittedly, I totally did not know NVMe’s were becoming a thing until a year ago, as I had been in the laptop-only space for a while or didnt need to optimize storage speed when connecting an existing drive to a secondhand motherboard. I like being ahead of the curve and am now curious whats next

ksec 5y ago
>I like being ahead of the curve and am now curious whats next Others correct me if I am wrong. NVMe in itself is an interface specification, people often use the term NVMe when they are meant M2, the Connector. You wont get a new connector in the pipeline. But the M.2 is essentially just 4 lane PCI-E express. So every time you get PCI-E express update, currently 4.0, 5.0 around the corner and 6.0 in final draft. 7.0 possibly within next 3-4 years. So you can expect 14GB/s SSD soon, 28GB/s in ~2024, 50GB/s within this decade assuming we could somehow get the SSD controller power usage down to a reasonable level.
- vmception 5y ago
  Hmm insightful, yes I recall noticing that connector/specification thing when I was trying to get the right size cards, had figured NVMe and M.2 were just synonyms but I see the cause for the correlation now So the NVMe card I added to an old motherboard’s PCI-E slot is really just PCI-E on PCI-E? yo dawg
  - wtallis 5y ago
    > So the NVMe card I added to an old motherboard’s PCI-E slot is really just PCI-E on PCI-E? Assuming that's a PCIe to M.2 adapter card, it's just rearranging the wires to a more compact connector. There's no nesting or layering of any protocols. Electrically, nothing changed about how the PCIe signals are carried (though M.2 lacks the 12V power supply), and either way you have NVMe commands encapsulated in PCIe packets (exactly analogous to how your network may have IP packets encapsulated in Ethernet frames).
- magicalhippo 5y ago
  > But the M.2 is essentially just 4 lane PCI-E express M.2 is a bit more complex[1] than that, sadly. [1]: https://en.wikipedia.org/wiki/M.2#Form_factors_and_keying https://en.wikipedia.org/wiki/M.2#Form_factors_and_keying
wtallis 5y ago
In the server space, SAS, U.2 and U.3 connectors are mechanically compatible with each other and partially compatible with SATA connectors. U.3 is probably the dead end for that family, but they won't disappear completely for a long time. Traditional PCIe add-in cards (PCIe CEM connector) are still around and also not going to be disappearing anytime soon, but are in decline as many use cases have switched over to other connectors and form factors, particularly for the sake of better hot-swap support. M.2 (primarily SSDs) is in rapid decline in the server space. It may hang on for a while for boot drives, but for everything else you want hot-swap and better power delivery (12V rather than 3.3V). The up and coming connector is SFF-TA-1002, used in the EDSFF form factors and a few other applications like the latest OCP NIC form factor. Its smaller configurations are only a bit larger than M.2, and the wider versions are quite a bit denser than regular PCIe add-in card slots. EDSFF provides a variety of form factors suitable for 1U and 2U servers, replacing 2.5" drives. The SFF-TA-1002 connector can also be used as direct replacement for the PCIe CEM connector, but I'm not sure if that's actually going to happen anytime soon. I haven't seen any sign that EDSFF or SFF-TA-1002 will be showing up in consumer systems. Existing solutions like M.2 and PCIe CEM are good enough for now and the foreseeable future. The older connectors sometimes need to have tolerances tightened up to support higher signal rates, but so far a backwards-incompatible redesign hasn't been necessary to support newer generations of PCIe (though the practical distances usable without retimers have been decreasing).

ksec 5y ago

>I like being ahead of the curve and am now curious whats next Others correct me if I am wrong. NVMe in itself is an interface specification, people often use the term NVMe when they are meant M2, the Connector. You wont get a new connector in the pipeline. But the M.2 is essentially just 4 lane PCI-E express. So every time you get PCI-E express update, currently 4.0, 5.0 around the corner and 6.0 in final draft. 7.0 possibly within next 3-4 years. So you can expect 14GB/s SSD soon, 28GB/s in ~2024, 50GB/s within this decade assuming we could somehow get the SSD controller power usage down to a reasonable level.

vmception 5y ago
Hmm insightful, yes I recall noticing that connector/specification thing when I was trying to get the right size cards, had figured NVMe and M.2 were just synonyms but I see the cause for the correlation now So the NVMe card I added to an old motherboard’s PCI-E slot is really just PCI-E on PCI-E? yo dawg
- wtallis 5y ago
  > So the NVMe card I added to an old motherboard’s PCI-E slot is really just PCI-E on PCI-E? Assuming that's a PCIe to M.2 adapter card, it's just rearranging the wires to a more compact connector. There's no nesting or layering of any protocols. Electrically, nothing changed about how the PCIe signals are carried (though M.2 lacks the 12V power supply), and either way you have NVMe commands encapsulated in PCIe packets (exactly analogous to how your network may have IP packets encapsulated in Ethernet frames).
magicalhippo 5y ago
> But the M.2 is essentially just 4 lane PCI-E express M.2 is a bit more complex[1] than that, sadly. [1]: https://en.wikipedia.org/wiki/M.2#Form_factors_and_keying https://en.wikipedia.org/wiki/M.2#Form_factors_and_keying

wtallis 5y ago

In the server space, SAS, U.2 and U.3 connectors are mechanically compatible with each other and partially compatible with SATA connectors. U.3 is probably the dead end for that family, but they won't disappear completely for a long time. Traditional PCIe add-in cards (PCIe CEM connector) are still around and also not going to be disappearing anytime soon, but are in decline as many use cases have switched over to other connectors and form factors, particularly for the sake of better hot-swap support. M.2 (primarily SSDs) is in rapid decline in the server space. It may hang on for a while for boot drives, but for everything else you want hot-swap and better power delivery (12V rather than 3.3V). The up and coming connector is SFF-TA-1002, used in the EDSFF form factors and a few other applications like the latest OCP NIC form factor. Its smaller configurations are only a bit larger than M.2, and the wider versions are quite a bit denser than regular PCIe add-in card slots. EDSFF provides a variety of form factors suitable for 1U and 2U servers, replacing 2.5" drives. The SFF-TA-1002 connector can also be used as direct replacement for the PCIe CEM connector, but I'm not sure if that's actually going to happen anytime soon. I haven't seen any sign that EDSFF or SFF-TA-1002 will be showing up in consumer systems. Existing solutions like M.2 and PCIe CEM are good enough for now and the foreseeable future. The older connectors sometimes need to have tolerances tightened up to support higher signal rates, but so far a backwards-incompatible redesign hasn't been necessary to support newer generations of PCIe (though the practical distances usable without retimers have been decreasing).