Move over M.2, here comes the XFM memory specification

Molematt

Posts: 36   +2
Why it matters: The JEDEC Solid State Technology Association has introduced a new Crossover Flash Memory (XFM) specification for NAND storage, designed to replace the existing M.2 form factor. Its significantly smaller form factor could help to bring replaceable storage into smaller devices that have traditionally only been able to fit soldered memory, but size isn't all that matters on that front.

The JEDEC JESD233 XFM Embedded and Removable Memory Device (XFMD) standard uses the NVMe logical interface over a PCI Express physical interface, meaning that XFMD cards will appear to their host devices just as an M.2 stick would. Although the standard uses only one or two lanes of the interface, the bandwidth of PCIe Gen 4 still gives it far higher data transfer speeds than UFS chips (like those pictured above), soldered eMMC storage, and removable SD storage.

The last is a particularly important point of comparison, given that the XFMD described in the JEDEC specification measured just 18 x 14 x 1.4mm (15 x 11 x 2.1mm) is closely comparable in size to a microSD card.

JEDEC says that the smaller standard would allow use in scenarios that would normally be limited to soldered storage, such as IoT and embedded applications -- although also notes that other highly portable devices would benefit from the new form factor, such as VR headsets, drones, and ultraportable laptops.

Memory manufacturer Kioxia has spoken out in favor of the new form factor, with senior director Atasushi Inoue claiming that the XFMD standard "will be used as a game changer for semi-removable storage in many electronic and IOT devices, taking advantage of its balanced performance, small size, and easy maintenance."

MediaTek also endorsed XFM, although it described the specification as enabling “new, expandable storage options for end users,” in contrast to Kioxia's view of semi-removable storage.

However, while the specified XFMD is small enough to potentially replace some soldered solutions, PCIe draws more power than the M-PHY interface currently used in UFS solutions, which might hurt adoption in particularly ultraportable battery-powered applications.

In addition, the data sheet makes no mention of DRAM caches that are key enablers of the performance of current high-performance SSDs, and if those are absent then XFMDs might find it difficult to unlock the full speed advantages of NVMe over their UFS or eMMC counterparts.

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This may be a long time coming with fabs at full capacity and a long backlog for chip companies that don't have the clout of an Apple or Tesla.
 
I like the idea of this eventually replacing both ssd cards and emmc modules and such. So these I can see replacing user storage but for "boot" drives and high performance that we see now with m.2 will probably end up with EDSFF or something similar to that: better form factor for the cooling capacity than m.2 but still compact.
 
I like the idea of this eventually replacing both ssd cards and emmc modules and such. So these I can see replacing user storage but for "boot" drives and high performance that we see now with m.2 will probably end up with EDSFF or something similar to that: better form factor for the cooling capacity than m.2 but still compact.

I've heard that before. I just don't see it in the consumer space. The smallest EDSFF drive is still 30mm larger than the more popular 80mm length nvme stick. Now going over 4GB on an 80mm nvme stick might be an issue but stick a tall finned heat spreader on it and you have a smaller EDSFF drive already. They do fit perfectly in the server/datacenter biz though.
 
I've heard that before. I just don't see it in the consumer space. The smallest EDSFF drive is still 30mm larger than the more popular 80mm length nvme stick. Now going over 4GB on an 80mm nvme stick might be an issue but stick a tall finned heat spreader on it and you have a smaller EDSFF drive already. They do fit perfectly in the server/datacenter biz though.
Well there's nothing inherently wrong with m.2 as it stands, it's near the limits of practicality in terms of what it can deliver vs what's needed to cool the drives right now but it really is way more speed than even most workstations need.

So in that regard I have to concede your argument at least partially. However, if there's a push to get even faster speeds which right now is unlikely unless technologies like Direct Storage really take off in a big way and start being far more in demand by consumers and "pro-sumers" and such.

If that's the case I don't think m.2 is very viable in terms of what you'd need to cool it down. And yes I'm aware that EDSFF is designed around data centers but there's no reason why consumer motherboards and cases couldn't accommodate them, specially if by the time those characteristics are in demand for the consumer segment it will probably have several years of maturity: you can easily see front panels being able to slot and cool something like an E1 or E1.S form factor but again it might take a completely different form if it comes to consumers I'm not 100% on that tbh.
 
Well there's nothing inherently wrong with m.2 as it stands, it's near the limits of practicality in terms of what it can deliver vs what's needed to cool the drives right now but it really is way more speed than even most workstations need.

So in that regard I have to concede your argument at least partially. However, if there's a push to get even faster speeds which right now is unlikely unless technologies like Direct Storage really take off in a big way and start being far more in demand by consumers and "pro-sumers" and such.

If that's the case I don't think m.2 is very viable in terms of what you'd need to cool it down. And yes I'm aware that EDSFF is designed around data centers but there's no reason why consumer motherboards and cases couldn't accommodate them, specially if by the time those characteristics are in demand for the consumer segment it will probably have several years of maturity: you can easily see front panels being able to slot and cool something like an E1 or E1.S form factor but again it might take a completely different form if it comes to consumers I'm not 100% on that tbh.

I generally agree with what you are saying. It may be a hybrid of what we have now. As a general rule hardware advancement follows engineering by making things smaller and more power efficient per watt. If larger drive capacity requires more power/cooling that may be the case. But in the consumer hard drive arena I'm not sure that is necessary, at least for now. If we leave high end graphic cards out of the equation that is LOL. As long as we can install (whatever format) HD's on a motherboard instead of running cables/power to a hard drive bay I'm all for wherever the tech takes us.
 
Great, as soon as I get used to M.2, another generation of storage is already there to displace it.
 
This isn't an M.2 replacement at all, I don't know where the author took that idea from. It's targeted at embedded and small factor devices and serves as an alternative to soldered memory* and memory cards: UFS, eMMC, SD cards etc. The news even mentions that explicitly, so I am even more confused by the idea it would make M.2 obsolete. It could be an alternative to M.2 in some larger devices like notebooks and consoles, but most of its usecases are vastly different.

*As JEDEC page says:
"XFMD is a new universal data storage media providing an NVMe® over PCI Express® interface in a small, thin form factor. The device is designed to bring replaceable storage to devices typically soldered down in IoT devices and embedded applications."
https://www.jedec.org/node/9067
 
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