News Chinese chipmaker unveils Optane-like storage class memory

[Admin]

Numemory has 64Gb and 128Gb storage class memory devices with industry-standard NAND interface that could be used for SSDs, expensive SSDs.

Chinese chipmaker unveils Optane-like storage class memory : Read more

 

[usertests]

Although it wasn't the smash hit that Intel and Micron had hoped, some companies definitely had use cases well suited to the characteristics of Optane/3D XPoint. New tiers of memory/storage are destined to reappear time and time again, unless we eventually get universal memory that can consolidate some of them.

With the relatively low capacities described in the article, the first stop may be AI products that need a lot of memory. If the AI model isn't changing often, the endurance hit won't be too bad.

 

[jkhoward]

My main computers all use an Optane OS drive to this day. I bought a spare 280 GB PCIe one recently on sale, and a 128(?) spare NVMe one for a laptop. This technology should have never died.

 

[JRStern]

Intel Optane never officially admitted what their technology was, either.
And it turned out to use too much power to write, generated too much heat, so couldn't stack like flash.
So it could never produce price/performance that fit between NAND and DRAM.
The idea that it could easily back up main DRAM in some useful way was a pipe dream.
So where is this stuff going?

>Numemory's NM101 chips can be used for SSDs that can load a 10GB high-definition video in just one second.

At what power level? With what kind of cooling? Or do we just let it melt after the demonstration.

 

[Findecanor]

When Optane ("3D cross point") was being sold, there did appear third-party software that did take advantage of it. There did appear datacenter solutions that took advantage of it. I've also read about several research papers about persistent data structures, file systems and databases that had been enabled by the existence of Optane.

If this Chinese firm has developed a successor for Intel's Optane, I do think there could be a niche ready for it.
But there need to be the right politics, the right marketing and similar speed and durability as Optane to make it attractive, or that niche will remain small.

Non-volatile memory technology is not a panacea: it is not going to change the world. At best, it is a middle-ground between DRAM and NAND Flash in both speed and longevity.
It still needs wear-levelling, overprovisioning and caching in DRAM protect it from wearing out prematurely, just like NAND Flash does.

 

[bit_user]

Xincun does not disclose further specifications of its devices, only briefly mentioning 'ultra-fast microsecond-level response times,' which is a very vague description of latency, to put it mildly. To put the number into context, Intel's Optane promised 10 ~ 15 microseconds read latency and over 200-microsecond write latencies, whereas modern 3D TLC NAND can boast 80 microseconds read latency and write latencies that are in the ballpark of hundreds of microseconds. By contrast, the latency of DDR5 SDRAM is 10 to 20 nanoseconds, depending on the exact memory subsystems.

I have a lot of respect for Anton, which makes it all the sadder when he gets something so basic, so wrong.
: (

The figure he quoted is for NVMe-based Optane SSDs, like the P4800X:

Source: https://www.anandtech.com/show/11930/intel-optane-ssd-dc-p4800x-750gb-handson-review/5
​

Even with the P5800X (second-gen, PCIe 4.0), this figure dropped to < 6 usec for QD1 4kB random reads (99th percentile):

Source: https://blocksandfiles.com/2020/12/...-new-optane-drives-one-is-worlds-fastest-ssd/
​

However, as you can also see from the above, the overwhelming amount of that 6 usec is spent in hardware, software, and firmware overhead. The actual 2nd gen Optane chips, themselves, had a latency of just 100 nsec (writes?) to 340 nsec (reads?) per 64 byte transaction.

FWIW, the time to transfer 4 kB of data at the nominal speed of PCIe 4.0 x4 is more than half of a microsecond, if my math is right. So, if you cut the read size down to just 64 B, to match how the PMem DIMM is being measured, it'd shave off only about 10% of that 6 usec figure and the SSD would still be a couple orders of magnitude worse than the DIMM.

 

[bit_user]

Although it wasn't the smash hit that Intel and Micron had hoped, some companies definitely had use cases well suited to the characteristics of Optane/3D XPoint. New tiers of memory/storage are destined to reappear time and time again, unless we eventually get universal memory that can consolidate some of them.

3D XPoint isn't the only solution to this problem.

"Micron’s nonvolatile DIMMs (NVDIMMs) combine the speed of DRAM with the persistent storage of NAND flash to remove I/O bottlenecks and deliver big performance"

https://my.micron.com/content/dam/micron/global/public/products/product-flyer/nvdimm-flyer.pdf
​

That's an old, DDR4-based product. I don't know if they've updated it for DDR5. I think this sort of thing is likely to live on CXL, in the future (if not already). That opens up a much more wider and practical array of form factors, especially if you have some form of battery backup. I think CXL only adds a couple hundred ns of latency, which should easily match what Intel achieved with their PMem 200 or 300 DIMMs being on the CPU's local memory channel.

Edit: here's a CXL-based memory module that combines NAND and DRAM to support persistence or tiering (which is called out as a separate use case):

Samsung CXL Solutions – CMM-H | Samsung Semiconductor Global

As AI and Machine Learning solutions continue to be deployed across data center infrastructures, it is important to optimize the balance between compute, memory, and storage resources to best support language model processing performance along with cost management of such resources.

semiconductor.samsung.com

 

[bit_user]

When Optane ("3D cross point") was being sold, there did appear third-party software that did take advantage of it. There did appear datacenter solutions that took advantage of it. I've also read about several research papers about persistent data structures, file systems and databases that had been enabled by the existence of Optane.

The key thing is to avoid syscall overhead (i.e. accessing it via the kernel), because that more than doubles the native latency of PMem DIMMs.

If you merely have a memory tiering solution, you can naively run large-memory apps and let the tiering system try to migrate pages (i.e. promoting "hot" pages and demoting "cold" ones). For some applications, being able to go straight to persistent storage from userspace is probably still necessary, especially if the data access pattern is sufficiently random and exhibits too little data reuse. Basically, database workloads. I can't think of anything other than server apps that fall into this category.

 

[bit_user]

My main computers all use an Optane OS drive to this day. ... This technology should have never died.

Here's the thing about that. Intel sold off all their SSD assets to SK Hynix, except for Optane, which they just killed instead. SK Hynix is a NAND maker with its own fabs. If 3D XPoint were truly a viable technology, going forward, I'm sure they would've taken those assets as well. I expect Intel would've sold them for a song, given the alternative was simply taking a total loss on it.

According to what I read, Optane was never profitable for Intel. More worryingly, it seemed unable to keep pace with density and cost reductions happening in both NAND and DRAM. While Optane performs much better than NAND, it's a couple order of magnitudes slower than DRAM and many orders worse than DRAM on endurance. So, it was caught in this weird niche and basically being squeezed from all sides.

I think @JRStern is also right about it having a problem with write efficiency, which could be a concern for datacenters and mobile applications.

I also looked into cold storage data retention and found that it seems even worse at that than NAND, which is quite the opposite of what I was hoping or expecting.

P.S. I'm not a hater, as I did snap up a P5800X when Optane was end-of-life'd. Turns out, I should've waited to buy it. Ebay currently has some new, Dell rebadged drives selling for less than half what I paid (including from well-rated US sellers). Anything above 400 GB is way overpriced, though.

 

[davidjkay]

being able to random access and write at byte/word level rather than large block and persistence in power failure can be a big boost to some database type applications and potentially ai... can mean saving on lots of io and complexity to deal with the limitations of ssd and dram...

eg a small change may require lots of io to log and be able to do commit or rollback... and it has to be done immediately to follow rules about not losing data if power failure...