Intel's SSD 710: Making Enterprise Storage More Affordable?
It's almost ironic that the enterprise segment, which can often put the highest-performance hardware to use most immediately, also has to be the most cautious with unproven technology. It has taken a long, long time for solid-state storage to earn its place in data centers, but now SSDs are smashing bottlenecks in the server world, just as they did on the desktop more than three years ago when Intel's X25-M first pushed them into the mainstream.
Back then, the enterprise-oriented X25-Es were putting up the most impressive numbers. However, they were both comparatively small and expensive, affecting their accessibility. Now, the SSD 710 presents us with what we must presume to be a much more mature product based on a controller that has evolved over a very long life and HET MLC memory claimed to outlast the compute-quality NAND used in desktop drives. At the same time, we're forced to accept a compromise. In the interest of pulling down prices and pushing higher-capacity models, performance gets de-emphasized through a 3 Gb/s controller.
Are enterprises willing to accept such a trade? That's hard for us to say. On one hand, our own research suggests that Intel sets the standard for SSD reliability. And a business previously limited to short-stroked hard drives might jump at the opportunity to pick up high-capacity solid-state storage for a lot less per gigabyte than the now-defunct X25-E. On the other, there are a number of applications that absolutely need as much throughput as possible, hence the growing popularity of PCIe-based SSD unconstrained by SATA.
Oh, but guess what? Intel has plans to address that segment, too, with its upcoming SSD 720, armed with SLC NAND and a PCI Express interface. More on that later.
What we can say for the SSD 720 is that Intel's HET MLC-based drive really should offer exceptional write endurance. Going by the numbers, we calculated a 1818 terabyte-written value for our 200 GB SSD 710. That's 17x times higher than the consumer-oriented SSD 320. It's not the 33x margin Intel suggested at IDF, but we can certainly attest to this drive's enterprise pedigree.
Initially, the company's warranty policy on the SSD 710 did worry us because it included some fairly non-standard verbiage. Most of Intel's SSDs have a flat three-year warranty (except for the SSD 320, which is five years), but the terms for the 710 are three years or when the media wear-out indicator (E9) reaches 1, whichever comes first. With a bit of clever math, however, we found that it would take 4.2 years to consume all of the 200 GB SSD 710's P/E cycles, assuming a 100% 4 KB random write workload, 24x7, at a queue depth of 32. That's about 880 GB per day of data, by the way. Compare that to a 300 GB SSD 320, which would be worn out in a year.
Introduce a bit of idle time and make two-thirds of the drive accesses reads and Intel's SSD 710 looks like it has more than six or seven years in it before potentially wearing out. And again, that's 24x7 activity. Surprisingly, sequential transfers turn out to be the enemy here. While write amplification is low, data moves at a pretty zippy 200 MB/s or so, moving up to 15.5 TB a day and potentially wearing the drive out significantly faster.
And so, with the SSD 710's enterprise chops fully explored, we settle in to the debate over cost. There's nothing like Intel's new drive on the market, so have to compare a 200 GB SSD 710 at $1200 to a 200 GB P300 at $2100. Intel is commendably introducing cost-conscious businesses to a relatively affordable eMLC-based product compared to its outgoing SLC-based solution. To that end, the SSD makes sense if you need lots of capacity and enterprise-class endurance. Performance-sensitive applications are still best-served by SLC-based drive like the P300. Intel plans to address its position in the that particular market soon, though, with its SSD 720.
