Endurance Matters And Management
There are a number of factors to consider before purchasing an SSD, and endurance is one of the most important considerations. Enterprise SSD vendors measure endurance in DWPD (Drive Writes Per Day), which denotes how many times you can write the full capacity of the SSD before it wears out, and/or TBW, which indicates how many TB you can write before the warrantied endurance expires. Unfortunately, because drives have different warranty periods and varying capacities, the equation can become a bit muddy. Vendors focus on providing two separate endurance strata; high-endurance models for write-centric workloads and low-endurance models for read-centric applications.
We boil SSD endurance metrics down to three easily digestible values to help demystify endurance, cost, and the advantage of extra capacity. We derive pricing information from vendor-provided MSRPs for unreleased products and average the prices we find at retail for shipping products (YMMV).
|2TB Intel DC P3520||960GB SK hynix PE3100||1.6TB Intel DC P3700||3.2TB Memblaze PBlaze4||3.2TB HGST SN150|
|NAND||IMFT 3D MLC NAND||SK Hynix 3D NAND V2||Intel 20nm HET MLC||Toshiba 15nm MLC||Toshiba 128Gbit A19nm eMLC NAND|
|Endurance PB/DWPD||2.49 / 3 (5yr)||1.36 / 1.3 (3yr)||43.8 / 17 (5yr)||17.3 / 3 (3yr)||29.2 / 5 (5yr)|
|Dollar Per GB||$0.56||~$1.00||$1.69||~$1.00||$2.74|
|Lifetime PBW Per TB Of Useable Capacity||1.245||1.423||27.375||5.406||9.125|
|Endurance (TB) Per Dollar||2.19||1.39||16.2||5.40||3.39|
|Cost Efficiency Index||4.38||1.33||25.92||17.28||10.85|
Intel specifically geared the DC P3520 for the lower end of the endurance spectrum, but it also has a much lower price point than just about any competing SSD on the market. We brought in the SK hynix PE3110 to serve as a similar low-endurance comparison point, but note that it uses the M.2 connection in tandem with its PCIe interface and NVMe protocol. We do not have firm pricing details for the PE3110 or the Memblaze PBlaze4, so we are using a $1 per GB estimate as a comparison point.
We calculate the Endurance Per Dollar of the varying SSDs, and the Intel DC P3520 and the PE3110 offer the lowest amount of endurance per dollar of the test pool. We expect the lower numbers due to the value-optimized read-centric designs, while the vendors designed the other SSDs for more intense write-centric workloads. The DC P3520 also features the lowest price-per-GB measurement of the test pool by a large margin, which will certainly garner a lot of attention.
Endurance and price aren't the only facets, though, because additional capacity also holds significant business value. Our Cost Efficiency Index (CEI) ropes extra capacity into the equation. We calculate CEI with an amalgamation of capacity, cost, and endurance by multiplying capacity by the endurance-per-dollar. The SK Hynix PE3110 falls to the bottom of the pool with the lowest CEI measurement, while the DC P3700 continues to offer a beastly combination of endurance, price, and capacity. The DC P3520 offers a nice mid-point between the more endurant and higher-priced models and features a well-balanced CEI measurement. If you are seeking a great balance from a value standpoint, the DC P3520 should be at the top of the list.
System Compatibility And Management Utility
The DC P3520 enjoys the broad compatibility of the standardized NVMe interface. We list the oldest OS version that supports the interface, but OS vendors incorporate NVMe into all newer OS revisions beyond what we list. You can slot it into Windows Server 2008 R2, and it supports the desktop Windows 7, RHEL 6.5, SLES11 SP3, XenServer 6.5, VMware ESXI 5.5, CentOS 6.5, and UEFI 2.3.1.
We tested in CentOS 7.3 with kernel 4.7. The updated kernel has the newest in-box NVMe driver, and Intel provides Windows users with a newer version to use with the DC P3520.
Intel’s SSD Data Center Tool is a well-traveled CLI utility that provides a wide range of functionality, such as SMART reporting, firmware updates, secure erase functionality, thermal monitoring and logging, latency tracking logs, configurable Power Governor Modes, and so on. The tool also has an endurance analyzer feature that allows the user to predict how long the SSD will last in its current environment, which is helpful.
The CLI tool works on both Windows and Linux, and is somewhat utilitarian, and has the most Spartan of designs, which is, of course, pretty much the definition of any CLI tool. Other vendors provide slick GUIs in dedicated APIs and web-based interfaces, but the Intel SSD Data Center Tool gets the job done with a minimum of fuss and a lightweight design. The CLI, while not as pretty as other offerings, has one of the most well-rounded feature sets we’ve used, so it certainly ranks among the very best.