Jump to content

First Optane Performance tests show benefits and limits of Intel's NVDIMMs

The AchieVer

Recommended Posts

The AchieVer

First Optane Performance tests show benefits and limits of Intel's NVDIMMs

Non-volatile Solid State Drives (SSDs) revolutionized data storage. Will Intel's non-volatile DIMMs do the same to servers? Researchers at UC San Diego just released their test results. Here's what you need to know.

                 Here's how Intel plans to change the mainstream processor market

Here's how Intel plans to change the mainstream processor market

Mainstream processors are Intel's bread-and-butter, but declining PC sales are putting the squeeze on the company. But Intel is turning to an old trick to get people to interested in its next-generation silicon.


The various NVDIMMs coming to market all promise to be both cheaper and more capacious than DRAM, with the added benefit of non-volatility and, often, lower power consumption. Over the last decade researchers have been exploring the many facets of how to best use their capabilities.

Finally, the first NVDIMM has come to market. Intel's Optane DC Persistent Memory Module sits on the processor's memory bus, is byte addressable - unlike block-based storage - and is much faster than any SSD.

There's no free lunch though. Optane's latency is higher than DRAM, it requires 2nd gen Cascade Lake Xeon processors, and offers widely different read and write bandwidth. 

 . . . its max read bandwidth is 33.2 GB/s and scales with thread count, whereas its max write bandwidth is 8.9 GB/s and peaks at only four threads. 

Optane operates either as memory or in App Direct mode. Memory mode

. . . uses Optane DC to expand main memory capacity without persistence. It combines a Optane DC PMM with a conventional DRAM DIMM that serves as a direct-mapped cache for the Optane DC PMM. The CPU and operating system simply see a larger pool of main memory. 

In App Direct mode Optane appears as separate persistent device. The system installs a special file system that Optane-aware apps can use simple load-store instructions and that ensures crash consistency.  

Intel loaned test systems to researchers at UC San Diego loaded with 3TB of 256GB Optane DIMMs, though 128 and 512GB capacities are available. Their first paper includes performance data for Optane as main memory, persistent storage, and, perhaps the most intresting, persistent memory. 


The team tested Optane with Memcache and Redis workloads, and found that performance dropped between 8.6 and 19.2 percent, using a DRAM cache. This sounds wrong, but remember, the server can now support 3TB of main memory, instead of only 192GB DRAM, vastly reducing storage traffic.


As storage, the DRAM cache is disabled, and the system sees a persistent, block-based, storage device. Linux supports several file systems, such as Ext4 and XFS, that can directly access Optane as a block device, as well as NOVA, a file system designed for persistent memory. 

The team tested several workloads, including SQLite, MySQL, RocksDB, and MongoDB. Compared to running on an SATA SSD, they found performance gains from 50 percent to 20x.  


The team modified versions of Redis and RocksDB to map into their address space to access directly with loads and stores. RocksDB performance increased 3.5x, while Redis achieved a modest 20 percent gain. 


These are very early days for NVDIMMs, but this research points to the possible performance gains from using high-density memory and storage sitting on the server memory bus. As with SSDs, there will be, no doubt, some serious application tuning required to take full advantage of Optane performance.

But there are two more interesting threads to follow. Intel isn't supporting Optane on non-Intel processors and it's Xeon only. Which means that, for most of us, Optane is a non-event.  

Second, Optane isn't the only game in town. Nantero's carbon nanotube (CNT) promises to be faster and less costly than Optane. Arm has licensed two other NVRAM technologies as well.  

Each of these competing technologies will have different performance envelopes and power requirements. NVDIMM vendors may end up battling for developer resources, based on application performance and market demand. 

The cloud companies are likely to be the first with large scale Optane deployments. I'm told Optane has been in volume production for some months, and who else could quietly soak up a lot of Optane volume?  

Bottom line: the NVRAM/NVDIMM revolution is just starting. It promises to be a wild ride.




Link to comment
Share on other sites

  • Replies 2
  • Views 407
  • Created
  • Last Reply
The AchieVer

Intel puts Optane memory and NAND storage together on H10 SSD

Due to appear in May, the 3D XPoint and storage combo is aimed at the thin laptop market.



Intel has announced a new member of its Optane series, the H10 that adds some of the company's 3D NAND storage beside its Optane 3D XPoint memory on a single M.2 drive. 

Initially, the H10 will be offered in three combinations: A 16GB Optane chip with 256GB storage; 32GB of 3D XPoint and 512GB of storage; and 32GB of Optane with 1TB of storage. 

Aimed the light and thin laptop market, Intel said it expects the largest two combinations to have the highest volume, and will target them at laptops over the $1,000 mark. 

The H10 will initially be available in 8th-generation Core U-based laptops in the United States through Best Buy in May, produced by the likes of Dell, HPI, and Asus. 

No pricing details were provided by Intel. 

Thanks to the use of Optane as a hot cache, the chip giant claims the H10 is able to boost the opening of documents by 2 times, launch games 60% faster, and open large media files 90% faster when compared to other SSDs, but only when a machine is multitasking. 


In May last year, Intel took the wraps off of its new top Optane performer -- the 905P. Available in either U.2 or HHHL configurations, the 480GB U.2 version was $600 at launch, while the 960GB half-height version was $1,200. 

That same month, the company also unveiled its first set of Optane DIMMs for Xeon Scalable chips. 







Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...