Last week, we took a look at Intel's first product based on their 3D XPoint non-volatile memory technology: the Optane SSD DC P4800X, a record-breaking flagship enterprise SSD. Today Intel launches the first consumer product under the Optane brand: the Intel Optane Memory, a far smaller device with a price that is 20 times cheaper. Despite having "Memory" in its name, this consumer Optane Memory product is not a NVDIMM nor is it in any other way a replacement for DRAM (those products will be coming to the enterprise market next year, even though the obvious name is now taken). Optane Memory also not a suitable replacement for mainstream flash-based SSDs, because Optane Memory is only available in 16GB and 32GB capacities. Instead, Optane Memory is Intel's latest attempt at an old idea that is great in theory but has struggled to catch on in practice: SSD caching.

Optane is Intel's brand name for products based on the 3D XPoint memory technology they co-developed with Micron. 3D XPoint is a new class of non-volatile memory that is not a variant of flash memory, the current mainstream technology for solid state drives. NAND flash memory—be it older planar NAND or newer 3D NAND flash—has fundamental limits to performance and write endurance, and many of the problems get worse as flash is shrunk to higher densities. 3D XPoint memory takes a radically different approach to non-volatile storage, and it makes different tradeoffs between density, performance, endurance and cost. Intel's initial announcement of 3D XPoint memory technology in 2015 came with general order of magnitude comparisons against existing memory technologies (DRAM and flash). Compared to NAND flash, 3D XPoint is supposed to be on the order of 1000x faster with 1000x higher write endurance. Compared to DRAM, 3D XPoint memory is supposed to be about 10x denser, which generally implies it'll be cheaper per GB by about the same amount. Those comparisons were about the raw memory itself and not about the performance of an entire SSD, and they were also projections based on memory that was still more than a year from hitting the market.

3D XPoint memory is not intended or expected to be a complete replacement for flash memory or DRAM in the foreseeable future. It offers substantially lower latency than flash memory but at a much higher price per GB. It still has finite endurance that makes it unsuitable as a drop-in replacement for DRAM without some form of wear-leveling. The natural role for 3D XPoint technology seems to be as a new tier in the memory hierarchy, slotting in between the smaller but faster DRAM and the larger but slower NAND flash. The Optane products released this month are using the first-generation 3D XPoint memory, along with first-generation controllers. Future generations should be able to offer substantial improvements to performance, endurance and capacity, but it's too soon to tell how those characteristics will scale.

The Intel Optane Memory is a M.2 NVMe SSD using 3D XPoint memory instead of NAND flash memory. 3D XPoint allows the Optane Memory to deliver far higher throughput than any flash SSD of equivalent capacity, and lower read latency than a NAND flash SSD of any capacity. The Optane Memory is intended both for OEMs to integrate into new systems and as an aftermarket upgrade for "Optane Memory ready" systems: those that meet the system requirements for Intel's new Optane caching software and have motherboard firmware support for booting from a cached volume. However, the Optane Memory can also be treated as a small and fast NVMe SSD, because all of the work to enable its caching role is performed in software or by the PCH on the motherboard. 32GB is even (barely) enough to be used as a Windows boot drive, though doing so would not be useful for most consumers.

Intel Optane Memory uses a PCIe 3.0 x2 link, while most M.2 PCIe SSDs use the full 4 lanes the connector is capable of. The two-lane link allows the Optane Memory to use the same B and M connector key positions that are used by M.2 SATA SSDs, so there's no immediate visual giveaway that Optane Memory requires PCIe connectivity from the M.2 socket. The Optane Memory is a standard 22x80mm single-sided card but the components don't come close to using the full length. The controller chip is far smaller than a typical NVMe SSD controller, and the Optane Memory includes just one or two single-die packages of 3D XPoint memory. The Optane Memory module has labels on the front and back that contain a copper foil heatspreader layer, positioned to cool the memory rather than the controller. There is no DRAM visible on the drive.

Intel Optane Memory Specifications
Capacity 16 GB 32 GB
Form Factor M.2 2280 B+M key
Interface PCIe 3.0 x2
Protocol NVMe 1.1
Controller Intel
Memory 128Gb 20nm Intel 3D XPoint
Sequential Read 900 MB/s 1350 MB/s
Sequential Write 145 MB/s 290 MB/s
Random Read 190k IOPS 240k IOPS
Random Write 35k IOPS 65k IOPS
Read Latency 7µs 9 µs
Write Latency 18µs 30 µs
Active Power 3.5 W 3.5 W
Idle Power 1 W 1 W
Endurance 182.5 TB 182.5 TB
Warranty 5 years
MSRP $44 $77

The performance specifications of Intel Optane Memory have been revised slightly since the announcement last month, with Intel now providing separate performance specs for the two capacities. Given the PCIe x2 link it's no surprise to see that sequential read speeds are substantially lower than we see from other NVMe SSDs, with 900 MB/s for the 16GB model and 1350 MB/s for the 32GB model. Sequential writes of 145 MB/s and 290 MB/s are far slower than consumer SSDs are usually willing to advertise, but are typical of the actual sustained sequential write speed of a good TLC NAND SSD. Random read throughput of 190k and 240k IOPS is in the ballpark for other NVMe SSDs. Random write throughput of 35k and 65k IOPS are also below the peak speeds advertised my most consumer SSDs, but on par with mainstream TLC and MLC SSDs respectively for actual performance at low queue depths.

Really it's the latency specifications where Optane Memory shines: the read latency of 7µs and 9µs for the 16GB and 32GB respectively are slightly better than even the enterprise Optane SSD DC P4800x, while write latency of 18µs and 30µs are just 2-3 times slower. The read latencies are completely untouchable for flash-based SSDs, but the write latencies can be matched by other NVMe controllers, but only because they cache write operations instead of performing them immediately.

The power consumption and endurance specifications don't look as impressive. 3.5W active power is lower than many M.2 PCIe SSDs and low enough that thermal throttling is unlikely to be a problem. The 1W idle power is unappealing, if not a bit problematic. Many M.2 NVMe SSDs will idle at 1W or more if the system is not using PCIe Active State Power Management and NVMe Power States. The Optane Memory doesn't even support the latter and will apparently draw the full 1W even in a well-tuned laptop. Since these power consumption numbers are typically going to be in addition to the power consumption of a mechanical hard drive, an Optane caching configuration is not going to offer decent power efficiency.

Meanwhile write endurance is rated at the same 100GB/day or 182.5 TB total for both capacities. Even though a stress test could burn through all of that in a week or two, 100GB/day is usually plenty for ordinary consumer use. However, a cache drive will likely experience a higher than normal write load as data and applications will tend to get evicted from the cache only to be pulled back in the next time they are loaded. More importantly, Intel promised that 3D XPoint would have on the order of 1000x the endurance of NAND flash, which should put these drives beyond the write endurance of any other consumer SSDs even after accounting for their small capacity.

Intel's Caching History
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  • BrokenCrayons - Monday, April 24, 2017 - link

    A desktop Linux distro would fit nicely on it with room for local file storage. I've lived pretty happily with a netbook that had a 32GB compact flash card on a 2.5 inch SATA adapter that had Linux Mint 17.3 on it. The OS and default applications used less than 8GB of space. I didn't give it a swap partition since 2GB was more than enough RAM under Linux (system was idle at less than 200MB and I never saw it demand more than 1.2GB when I was multi-tasking). As such, there was lots of space to store my music, books, and pics of my cat. Reply
  • ddriver - Monday, April 24, 2017 - link

    And imagine how well DOS will run. And you have ample space for application and data storage. 32 gigs - that's what dreams were made of in the early 90s. Your music, books and cat pics are just icing on the cake. Let me guess, 64 kbit mp3s right? Reply
  • BrokenCrayons - Monday, April 24, 2017 - link

    I'm impressed at the level of your insecurity. Reply
  • mkozakewich - Thursday, April 27, 2017 - link

    I've made the decision to never read any comment with his name above, but sometimes I accidentally miss it. Reply
  • DanNeely - Monday, April 24, 2017 - link

    Looking at the size of it, I'm wondering why they didn't make a 48GB model that would fill up the 80mm stick fully. Or, and unless the 3xpoint dies fully fill the area in the packages make them slightly smaller to support the 2260 form factor (after accounting for the odds and ends at the end of the stick the current design it looks like it's just too big to fit on the smaller size). Reply
  • CaedenV - Monday, April 24, 2017 - link

    Once again, I have to ask.... who on earth is this product for?
    So you have a cheap $300 laptop, which is going to have a terrible display, minimal RAM, and a small HDD or eMMC drive... are they expecting these users to spring for one of these drives to choke their CPU?

    Maybe a more mainstream $5-900 laptop where price is still ultra competitive. What sales metric does this add to which will promote sales over a cheaper device with seemingly the same specs? Either it will have a SSD onboard already and the performance difference will be un-noticed, or it will have a large HDD and the end-user is going to scratch their heads wondering why 2 seemingly identical computers have 4GB of RAM and 1TB HDD, but one costs $100 more.

    Ok, so maybe it is in the premium $1-2000 market. Intel says it isn't aiming at these devices, but they are Intel. Maybe they think a $1-2000 laptop is an 'affordable' mass-market device? Here you are talking about ultrabooks; super slim devices with SSDs... oh, and they only have 1 PCIe slot on board. Just add a 2nd one? Where are you going to put it? Going to add more weight? More thickness? A smaller battery? And even after you manage to cram the part in one of these laptops... what exactly is going to be the performance benefit? An extra half a second when coming out of sleep mode? Word opens in .5 sec instead of .8 sec? Yes, these drives are faster than SSDs... but we are way past the point of where software load times matter at all.

    So then what about workstation laptops. That is where these look like they will shine. A video editing laptop, or desktop replacement. And for those few brave souls using such a machine with a single HDD or SSD this seems like it would work well... except I don't know anyone like that. These are production machines, which means RAID1 in case of HDD failure. And this tech does not work with RAID (even though I don't see why not... seems like they could easily integrate this into the RAID controller). But maybe they could use the drive as a 3rd small stand-alone render drive... but that only works in linux, not windows. So, nope, this isn't going to work in this market either.

    And that brings us to the desktop market. For the same price/raid concerns this product really doesn't work for desktops either, but the Optate SSDs coming out later this year sound interesting... but here we still have a pretty major issue;
    SATA3 vs PCIe m.2 drives have an odd problem. On paper the m.2 drives benchmark amazingly well. And in production environments for rendering they also work really well. But for work applications and games people are reporting that there is little to no difference in performance. Intel is trying to make the claim that the issue is due to access time on the controllers, and that the extremely fast access time on Optane will finally get us past all that. But I don't think that is true. For work applications most of the wait time is either on the CPU or the network connection to the source material. The end-user storage is no longer the limiting factor in these scenarios. For games, much of the load time is in the GPU taking textures and game data and unpackaging them in the GPU's vRAM for use. The CPU and HDD/SSD are largely idle during this process. Even modern HDDs keep up pretty well with their SSD brethren on game load times. This leads me to believe that there is something else that is slowing down the whole process.

    And that single bottleneck in the whole thing is Intel. It is their CPUs that have stopped getting faster. It is their RAM management that rather sucks and works the same speed no matter what your RAM is clocked at. It is the whole x86 platform that is stagnant and inefficient which is the real issue here. It is time for Intel to stop focusing on its next die-shrink, and start working on a new modern efficient instruction set and architecture that can take advantage of all this new tech! Backwards compatibility is killing the computer market. Time to make a clean break on the hardware side for a new way of doing things. We can always add software compatibility in an emulation layer so we can still use our old OSs and tools. Its going to be a mess, but we are at a point where it needs to be done.
    Reply
  • Cliff34 - Monday, April 24, 2017 - link

    It seems to me that this product doesn't really make sense for your average consumer. Let's assume you don't need to upgrade your hardware to use Optane memory as cache, why not just spend the money to get a faster and a bigger SSD drive?

    If that's the case, wouldn't it limited to only a few specific case where someone really need the Optane speed?
    Reply
  • mkozakewich - Thursday, April 27, 2017 - link

    An extra 4 GB of DDR4 seems to be $30-$40, so getting 16 GB of swap drive for the same price might be a good way to go.
    I agree that using it for caching seems a little pointless.
    Reply
  • zodiacfml - Monday, April 24, 2017 - link

    Wow, strong at random perf where SSDs are weak. I guess this will be the drive for me. Next gen please. Reply
  • p2131471 - Monday, April 24, 2017 - link

    I wish you'd make interactive graphs for random reads. Or at least provide numbers in a table. Right now I can only approximate the exact values. Reply

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