Last week I highlighted a pair of ARM processors with very different use cases, and now the pattern repeats as Western Digital, a company synonymous with hard-disk technology, introduces a pair of SSDs for markedly different use.
The Western Digital Ultrastar DC SN630 NVMe SSD and the Western Digital CL SN720 NVMe SSD both sport internally developed controller and firmware architectures, 64-layer 3D NAND technology and a NVMe interface, but that’s about where they end.
The SN630 is a read-intensive drive capable of two disk writes per day, which means it has the performance to write the full capacity of the drive two times per day. So a 1TB version can write up two 2TB per day. But these drives are smaller capacity, as WD traded capacity for endurance.
The SN720 is a boot device optimized for edge servers and hyperscale cloud with a lot more write performance. Random write is 10x the speed of the SN630 and is optimized for fast sequential writes.
Both use NVMe, which is predicted to replace the ageing SATA interface. SATA was first developed around the turn of the century as a replacement for the IDE interface and has its legacy in hard disk technology. It is the single biggest bottleneck in SSD performance.
NVMe uses the much faster PCI Express protocol, which is much more parallel and has better error recovery. Rather than squeeze any more life out of SATA, the industry is moving to NVMe in a big way at the expense of SATA. IDC predicts SATA product sales peaked in 2017 at around $5 billion and are headed to $1 billion by 2022. PCIe-based drives, on the other hand, will skyrocket from around $3.5 billion in 2017 to almost $20 billion by 2022.
So the new SSDs are replacement not only for older 15k RPM hard disks but SATA drives as well with specific use cases.
“The data landscape is rapidly changing. More devices are coming online and IoT is trying to connect everything together. The world is moving from on-prem to the cloud but also from the core cloud to the edge,” said Clint Ludeman, senior manager for product marketing for data center devices at Western Digital.
Reducing latency is becoming an issue, whether it’s a roundtrip from device to data center and back again or reducing latency at the core of the data center. “Big Data opens up opportunities, but then you gotta do something with data. Fast SSDs allow you to do something with the data,” he said.
That’s where the targeted products come into play. “We do see a shift from traditional server architecture, where an OEM would throw a server out there and not know what was running on it. Now we’re seeing a case where customers know their workloads and know their bottlenecks. That’s how we’re designing purpose-built products. As software stacks mature, you see different bottlenecks. It’s a continual thing we’re chasing,” he said.
And by going to NVMe they are able to reduce latency in the software stack to microseconds rather than the milliseconds that a hard disk works on. “We would have performance bottlenecks you couldn’t unlock with SATA or SAS interfaces. Now we can do real-time computing,” said Ludeman.
The CL SN720 is shipping now. The Ultrastar DC SN630 SSD is currently sampling with select customers with broad availability expected in April.
Thanks to Andy Patrizio (see source)