Seagate’s recent ‘Rethink Data’ report predicts that enterprise data will increase at an average annual growth rate of 42.2% over the next two years. It identifies a number of factors as catalysts which include the increased use of analytics, cloud migrations and the proliferation of IoT devices.
Coming close on the heels of its recently announced 18TB IronWolf Pro NAS model, the fifth-generation Exos X18 18TB ST18000NM000J shows Seagate is up to these growth challenges. Delivering the industry’s highest rack storage density, it targets a wide range of enterprise applications such as Big Data, massive scale-out data centers, data backup, centralized surveillance, hyperscale and cloud data centers.
Available with SATA III or SAS3 interfaces, the Exos X18 18TB incorporates a range of innovative technologies designed to deliver high reliability, low latency, reduced power consumption and top performance. In this review, we put the X18 SATA model through its paces in the lab and subject it to a range of real-world performance tests.
Exos X18 18TB ST18000NM000J Enterprise features
Seagate’s 18TB ST18000NM000J IronWolf Pro model is aimed firmly at the SMB storage market and is limited to NAS appliances with up to 24 bays. The Exos X18 has none of these restrictions making it the ideal choice for data centers that want to build huge storage arrays.
Along with its very competitive pricing, other features that make the Exos X18 perfect for enterprises are its 2.5M hour MTBF rating, 550TB yearly workload and enhanced caching. Seagate also offers SED (self-encrypting drive) versions and all models come with a generous 5-year warranty.
The X18 only introduces a few minor improvements over the X16 as this helium-filled, 7,200rpm drive has the same 9 platters, 18 TDMR (two-dimensional magnetic recording) heads and 256MB of cache. Recording density has been increased from 2,336Kb/in to 2,470Kb/in allowing Seagate to squeeze 2TB onto each platter.
P
erformance also sees a modest boost as the X18 has a maximum sustained transfer rate of 270MB/sec – a 9MB/sec increase over the X16. As with previous Exos generations, Seagate offers a Hyperscale SATA model tuned for large data transfers and offering a boost in random write performance.
Commendably, Seagate has kept the idle power consumption exactly the same as the X16 which is 5.3W. This matters to data centers with 1000s of drives as this allows them to upgrade rack storage capacity without increasing overall power consumption and running costs.
Other noteworthy features are Seagate’s PowerChoice and PowerBalance technologies where the former is designed to offer significant power savings during prolonged periods of inactivity. It uses a set of idle and standby modes that gradually reduce consumption the longer the drive remains in an idle state and can even stop the disks completely if required.
PowerBalance is aimed at environments with high random read/write operations and can be used to balance seek performance with lower power consumption. Neither of these technologies are new, having been introduced in the original Exos models but they can be of great benefit to data centers that want to exert more control over power consumption.
Lab test setup
The Exos X18 is designed for use in multi-drive RAID arrays so, for real-world performance testing, we used the lab’s Qnap’s TVS-882BR NAS appliance. As one of Qnap’s high-end SMB models, this 8-bay desktop appliance is equipped with a 3.6GHz quad-core Intel Core i7-7700 CPU and 32GB of DDR4 memory.
ATTO Celerity FC-164P HBA with quad 16Gbps FC ports + QNAP’s TVS-882BR + 4 x 18TB ST18000NM000J
Qnap’s QTS system software and apps were loaded on a dedicated mirrored array comprising two enterprise-class 1.92TB Micron 5200 Max SATA SSDs. For performance testing, we fitted four 18TB Exos X18 SATA models and created a dedicated 49TB RAID5 storage pool.
The QTS software has integral support for Fibre Channel so for high-performance testing, we installed an ATTO Celerity FC-164P HBA with quad 16Gbps FC ports in the appliance. Our test host was a Dell PowerEdge T640 tower server with dual 2.1GHz 22-core Xeon Scalable Gold 6152 CPUs, 384GB of DDR4 plus an ATTO Celerity FC-164P HBA and running Windows Server 2019.
We created a dedicated 1TB FC LUN on the test drive array and mapped it to the server over a dual-port 32Gbps MPIO FC connection. Tests were conducted using Iometer configured with 256KB transfer request sizes for testing maximum sequential and random read/write rates and 4KB request sizes to measure IOPS throughput.
Exos X18 18TB ST18000NM000J Performance analysis
Testing the Exos X18 18TB ST18000NM000J in a RAID array and over high-performance fibre channel connections to a host system gives us the opportunity to show how they behave in a real world business environment. Also, this is the same lab environment used to test 16TB and 18TB data center drives from Seagate, Toshiba and Western Digital (WD) so we could directly compare performance results.
The Exos X18 is clearly capable of delivering an impressive performance that easily matched our results from WD’s 18TB DC H550. In our Iometer sequential read and write tests, the Exos X18 delivered impressive speeds of 3,150MB/sec and 3,123MB/sec.
For random read performance, the Exos X18 delivered identical results to the sequential read tests. Our 100% random write test is a worse-case scenario as few businesses will have these kinds of workloads but we found the Exos X18 ST18000NM000J offered results very similar to those from the competition.
Seagate also returned excellent results in our throughput tests. Sequential read and write rates were measured at a steady 300,600 IOPS and 234,500 IOPS while random read and write tests returned 300,400 IOPS and 3,140 IOPS.
Conclusion
As Seagate’s largest enterprise-class hard disk to date, the Exos X18 18TB ST18000NM000J offers data centers a great combination of high capacity and reliability. Performance is also on the money with the X18 delivering excellent results across the board in our real-world tests.
It does cost a few dollars more than WD’s 18TB UltraStar DC HC550 WUH721818ALE6L4 but Seagate’s PowerChoice and PowerBalance features give data center admins the opportunity to claw back some of these initial costs in the long term with the potential to further reduce power consumption. Combining all these features together makes Seagate’s Exos X18 a great choice for enterprises struggling to meet current and future storage challenges in rack-dense data centers.
