In short: As we put together to enter the zettabyte period, producers equivalent to Western Digital are getting artistic with new methods to enhance SSD technology. The corporate’s first ZNS SSD guarantees to make an actual distinction in efficiency and value for hyperscalers that deal with cloud, analytics, and machine studying.
As soon as an costly luxurious that got here in smaller capacities, SSDs have turn out to be commonplace in fashionable PCs because of ever reducing costs per gigabyte. Their pace has been a promoting level for top finish methods, from enterprise PCs to workstations and now consoles that leverage flash storage to permit builders to create bigger, extra advanced sport worlds.
The first generations of shopper SSDs initially did not exploit the full potential of flash technology as they used present HDD interfaces which had been comparatively restricted by way of bandwidth and used a distinct communication protocol that was optimized for spinning magnetic storage. The issue was partly solved with the introduction of PCIe SSD drives in 2007 and the NVMe protocol in 2011, and right this moment we’ve shopper drives able to unbelievable speeds in extra of 7,000 megabytes per second.
Nevertheless, these two applied sciences aren’t sufficient to use the parallelized I/O structure of flash storage for the lowest doable latency and guarantee elevated endurance in multi-level cells used to make excessive capability SSDs. And these limitations are significantly vital in information facilities, the place latency and complete price of possession are key issues.
That is the place the Zoned Namespaces Storage (ZNS) initiative is available in. A ZNS SSD borrows the software program stack from SMR HDDs and locations information sequentially into zones, which reduces write amplification in addition to the share of the uncooked capability that must be reserved for the goal of over provisioning. This fashion, you need to use extra of the uncooked capability of the drive, resulting in financial savings that shortly add up when that you must buy numerous drives.
One other benefit of this strategy is that since ZNS operates with massive zones as a substitute of 4K blocks, it would not have to carry out a whole lot of background rubbish assortment when in comparison with conventional strong state storage. Which means that real-world learn and write speeds are extra constant, and since information dealing with and administration is finished by the host, there’s much less want for a big DRAM cache on the gadget.
This week, Western Digital — considered one of the huge proponents of ZNS — revealed the Ultrastar DC ZN540, which is the first drive that encompasses these ideas into an precise product. The corporate says single Ultrastar DC ZN540 drive can substitute as much as 4 standard SSDs whereas offering decrease latencies, larger throughput, and higher endurance.
The brand new SSD makes use of 96-layer 3D QLC NAND reminiscence and a customized dual-port NVMe 1.3c-compliant controller that totally helps the ZNS Command Set 1.zero specification. That is an enterprise SSD that is available in a U.2 form-factor as a drop-in alternative for drives in present servers. It makes use of the identical software program stack as shingled magnetic recording (SMR) HDDs, however the key right here is that Western Digital needs to show that QLC NAND can reliably be utilized in the information middle whereas decreasing the complete price of possession when in comparison with present options.
The corporate claims the Ultrastar DC ZN540 is able to 4x the throughput of standard SSDs, with as much as a 57 p.c enchancment in latency when tackling write-heavy workloads. In testing towards a real-world software setting like RocksDB, the new drive delivered 2.5x decrease latencies whereas operating 32 random learn threads of key-value pairs. And these enhancements are additionally coming to different databases like MySQL.
For now, ZNS is restricted to enterprise SSDs like the Ultrastar DC ZN540, which is simply obtainable to some choose prospects of Western Digital. Nevertheless, the enhancements introduced by the new strategy do not require producers to make any adjustments to present SSD controllers, which suggests they might be applied with firmware adjustments on present drives as properly.