Optane is the Intel brand name for a memory product called 3D XPoint (pronounced “cross point,” not “ex point”). 3D XPoint-based memory was also sold by Micron under the brand name QuantX. Both companies jointly developed the 3D XPoint memory technology. 3D XPoint was announced in 2015 and reached the market in 2017. In 2021 and 2022, however, Micron and Intel closed their respective divisions working on the technology and related products, effectively killing the concept.
What Set Optane Apart?
Optane was an exciting memory concept because it stepped away from traditional memory storage methods. Optane didn’t store data bits as an electrical charge, or lack thereof. Optane’s actual storage method is a little unclear. Intel’s marketing information differs from observations from third parties with electron microscopes and other high-tech gear needed to look at the memory cell structure. It operates under the principles of PCM or ReRAM.
PCM stands for Phase Change Memory, while ReRAM stands for Resistive RAM. The physics behind both are slightly different, but the overall concept is the same. If you provide a large amount of current for a short amount of time, you can quickly heat and cool the storage material. This causes fine structures in the material to break down, increasing its resistance.
By providing a lower level of current over a slightly longer time period, you can cause a different change in the material. When heated more slowly it cools in a crystalline form which conducts electricity well. By applying a much smaller amount of current, you can measure whether the cell is conductive, allowing you to determine which state it’s in, reading a 1 or 0. Because of the storage method, Optane was non-volatile, meaning it didn’t lose stored data when power is lost.
What Was Optane Designed For?
SSDs are pretty fast compared to HDDs. Still, they’re slow compared to DRAM. Unfortunately, while RAM is a lot faster, it’s also a lot more expensive and requires more space. Optane was marketed as a missing link storage tier, somewhere between DRAM and NAND flash in performance. In reality, though, performance figures were a little more complex than that.
The design concept meant Optane fundamentally differed in technology from NAND flash and DRAM. This difference opened up new opportunities for performance and suggested promise for future developments. DRAM and NAND flash have taken decades to reach their current performance levels. Optane was able to match or exceed cutting-edge NAND flash in some regards and had performance characteristics somewhat reminiscent of RAM, if not quite at that level yet. The fact that Optane had this level of performance with so little development suggested great things for it after a few decades of optimisation.
Intel released Optane products in two formats. The first was SSDs using Optane memory. In benchmark tests, Optane SSDs generally performed exceptionally competitively. The other format was as a DIMM to go in a standard RAM slot. On supported Intel platforms (motherboard, chipset, and CPU), this DIMM could be configured as the main system memory while pushing the DRAM to act as an L4 cache.
As a high-performance, low-latency memory architecture, Optane was intended to act as an intermediate memory level between DRAM and storage. Long-term plans hope to be able to replace one or both technologies.
Advantages and Disadvantages
Optane was generally able to keep pace with the top-of-the-line SSDs in areas where the peak bandwidth of PCIe connections mostly limited them. In some tests, they outperformed the rest of the SSD market. The two key stats were access latency and IOPS. Optane SSDs were also drop-in compatible as they presented to the system as standard SSDs.
Unfortunately, while Optane’s high-performance capabilities let it compete with top-end SSDs, it was significantly more expensive than NAND flash to produce. This left two options. Intel could sell models with competitive capacity at sky-high prices or at similar price points but with reduced capacity. Intel opted to sell lower-capacity models, at least directly to consumers.
Compared to RAM, Optane was slower, but not by a considerable amount. Its latency was twice as high, but that’s still much faster than NAND flash was. The significant winning factor over RAM, however, was the price. As much as Optane couldn’t compete with NAND on cost per unit of capacity, DRAM couldn’t compete with Optane.
So, while the Optane DIMM modules used as main memory were slower than DRAM, they offered significantly larger capacities at much lower price points. To make It better, most of the performance loss wouldn’t be recognized because the DRAM would act as a substantial L4 cache tier. This made Optane a desirable option to organizations with use cases involving storing large data sets in memory.
Conclusion
Optane was an Intel brand name for 3D XPoint memory. It operated entirely differently from NAND and DRAM. Rather than storing an electric charge in a cell, it used Phase Change Memory. This changes the electrical resistance of the cell through clever physics. Optane offered performance comparable to high-end NAND flash SSDs. In some performance characteristics, it was closer to RAM. This allowed it to be sold as both a middle ground and a potential replacement for both.
Optane had lots of promise. Performance was high straight away and the technology was relatively near the start of the development process, at least compared to the much more mature NAND and DRAM. Unfortunately, for Intel and Micron, in the years after its introduction, 3D XPoint memory products like Optane, didn’t see large-scale market acceptance. This was likely primarily due to the high cost. Continuing development was relatively slow.
There were no significant breakthroughs to reduce the cost significantly or to stand out enough from DRAM and NAND flash to be worth the high asking price for the average consumer. With the product divisions shut down, the technology is essentially dead. Existing products will likely continue to be sold while stocks last, so if one suits your needs get it while you can.
