
With the latest 18TB enterprise hard disk drives (HDDs) garnering all the glory, it’s easy to forget that many businesses don’t need such high capacities and can’t justify the higher expenditure. Applications such as near-line storage, server-bound workloads and mid-range storage systems can get by with smaller capacity, lower cost HDDs and Toshiba’s latest MG08-D HDDs are designed to satisfy these requirements.
Available in 4TB, 6TB and 8TB capacities, the MG08-D series is a welcome update to Toshiba’s venerable MG04 family which was first launched way back in 2014. The new drives are aimed at mission-critical workloads and take many of the advanced technology features from their larger MG08 brethren to provide reliable 24/7 operations.
On review, we have the MG08ADA400E 4TB SATA model which provides 512e (emulation) sectors and is also offered in 4Kn (native) and 512n sector versions. This allows businesses running legacy applications to safely upgrade from the older MG04 models and all three capacities are also available with a 12Gbps SAS3 interface.
MG08ADA400E Hard disk features
The 4TB MG08-D is a 7,200rpm spinner, employs CMR (conventional magnetic recording) and only has three platters. This keeps costs down as the reduced number of components means it can be air filled and doesn’t need a more expensive helium-filled enclosure sealed with precision industrial welding.
The drive brings in a lot of new features that will appeal to enterprises. The older MG04 drives have an MTTF (mean time to failure) rating of 1.4M hours and the MG08-D increases this hugely to 2M hours.
The 550TB yearly workload rating and generous 5-year warranty haven’t changed but the MG08 has a lower idle power rating of 4.07W as opposed to the MG04’s 6W. Performance gets a boost as the MG08 receives a doubling in cache memory to 256MB and its maximum sustained transfer rate of 243MiB/s is a 25% improvement over the 195MiB/sec of the MG04ACA400E
As the member of the MG08 family, the drive gets the benefit of a number of advanced technologies. Vibration in multi-drive storage arrays and appliances running 24/7 operations can be a major issue as hard disks in close proximity to each other can accelerate hardware failures and errors.
Toshiba’s Stable Platter Technology minimizes vibration by stabilizing the motor shaft at both ends for improved tracking accuracy and maximum read and write performance. All MG08 drives feature built-in rotational vibration (RV) sensors so multiple drives can operate reliably when mounted closely together in a storage array or appliance. The RV sensors allow them to compensate for rotational vibration that occurs within the drive or externally so they can safely maintain high read and write speeds.
Another valuable feature is Toshiba’s Persistent Write Cache (PWC) technology which is designed to protect data being written to the disk in the event of a power interruption or failure. The drive employs a flash-based cache to save the data which is written back when the power supply has been restored.
Models that support Toshiba’s Sanitize Instant Erase (SIE) feature set are also available. Toshiba is particularly vague about SIE but we believe these drives support the long established SATA T13 ‘crypto scramble’ and SAS T10 ‘crypto erase’ standards that allow data recorded on the HDD to be invalidated ‘in a blink’ as opposed to a lengthy full disk wipe.
Lab test setup
The MG08ADA400E targets use in storage appliances and in multi-drive RAID arrays so, for real-world performance testing, we used Qnap’s TVS-882BR. 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 4TB MG04ACA400E
The QTS system software and apps were all loaded on a dedicated mirrored array comprising two enterprise-class 1.92TB Micron 5200 Max SATA SSDs. For performance testing, we fitted four MG08ADA400E drives and created a dedicated 11TB RAID5 storage pool.
As Qnap has implemented Fibre Channel support in QTS, we took advantage of this high-performance feature and 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.
MG08ADA400E Performance analysis
Testing the Toshiba MG08-D drives in a RAID array and over high-performance fibre channel connections to a host system allowed us to see how they behave in a real world business environment. Furthermore, as the rig was the same as the one used to test 16TB and 18TB drives from Seagate, Toshiba and Western Digital, we could directly compare performance results.
The MG08-D drives impressed as they put in a very creditable performance. In our Iometer sequential read tests, the array returned the same 3,150MB/sec as the latest 18TB drives and although write speeds dropped to 3,094MB/sec this was only 29MB/sec less than Seagate’s Exos X18.
Random read performance was up there with the best as Toshiba returned a tidy 3,150MB/sec. Our 100% random write test is a worse-case scenario as few businesses will have these kinds of workloads but the MG08-D still mustered a reasonable rate of 70MB/sec.
I/O throughput was generally less than the larger drives with Iometer reporting sequential read and write rates of 282,600 IOPS and 203,500 IOPS. Random read and write throughput was also slightly slower at 280,300 IOPS and 2,660 IOPS.
Conclusion
Toshiba’s MG08-D family of air-filled drives are well suited to a wide range of business storage applications where TCO is of higher concern than capacity. They are more power efficient than the previous generations, offer a significantly higher MTTF and deliver a substantial increase in performance over them as well.
The drives posted respectable performance numbers in our real world tests and although lower than the current crop of 16TB and 18TB drives, will be perfectly acceptable for less demanding workloads. With a price tag of $149, the 4TB MG08-D looks to be a good value and enterprises running mission critical workloads will approve of the inclusion of all key technology features from the current MG08 range which increases reliability in rack dense environments.