HGST 5TB and 6TB Deskstar NAS Drives Review


Having had wind we received drives from HGST for review I rapidly made my presence felt at the warehouse incoming door to grab the box before anyone else could even get a whiff of them.

You see I had insider information we were to receive 5TB and 6TB HGST NAS drives pre-launch for review purposes, and their arrival was imminent. Having secured the boxes they were whisked away, a quick examination of the shipping label revealed our details were correct but the senders details were somewhat ambiguous, no mention of HGST, immediately my heart sank to the bottom of the pit still I thought, trying to console myself all may not be lost.

Opening the box revealed the drives from HGST, wow, finally the NAS drives both the 5TB and 6TB had arrived, the hyper in me kicked in. Why all the excitement? Well, the HGST 4TB NAS drives have been one of the most reliable drives we have tested and used, in fact I am proof of that personally, as I have eight of them installed in my 8-bay NAS at home. Proof of the pudding is in the eating of it and that is exactly what I have done, they have been flawless, great reliability and performance. So, these new beauties were a breadth of fresh air, and they are going on test immediately.

hgst-upcloseThe HGST Deskstar NAS drives are all 7200rpm while Seagate and WD are all below 7200rpm, 5900rpm and 5400rpm respectively. The exception to the rule is the WD RED PRO drives that are supposed to be 7200rpm, but these have totally eluded us since the announcement and WD has not even responded to our request for review product, we’re totally dumbfounded! Seagate are still wondering around planning their assault on the 6TB NAS market it seems with a menial attempt of a desktop version that leaves a lot to be desired from a performance standpoint, and we are not privy to what their plans are for this space.

Customers wishing to use NAS drives for their NAS servers don’t exactly have too many choices and so the HGST with 7200rpm really is it, and it’s a bonus that it beats the pants off the others in performance.

hgst-drivesHGST claims the NAS drives are ideal for home and small commercial NAS servers but we would comfortably recommend using these drives as an integration solution for NAS servers up to 8-bays and maybe stretch to 10-bay desktop servers. The determining factor for capacity loading is the amount of data that is being transferred per annum. As a rule of thumb if your data transfer will exceed 160TB per year then you are best positioned to take advantage of what the Enterprise drives have to offer. This formula is based on realistic data we have gathered over an extended period of time deploying real-time data.

Whilst the size of data usage is important, another aspect often neglected in the assessment of drive suitability is vibration tolerance, not so much in single drive situations but, more so in RAID based array systems. This feature plays its part in the reliability and longevity of the drives, more often than not a determination between failure and success.

Rotational Vibration is part of a larger problem for disk drives: keeping read/write heads on track with the embedded servo design the head-positioning information is placed on the same track as the data, enabling the head to check its position as it reads data. The problem is that if the head gets knocked off track it will take the entire rotation of the disk to get back on track again, in disk drive terms this is an eternity.

Disk drives are intricate and the problem occurs when you have a few drives together in close proximity like in a disk array. Nowadays of course we are not talking about a few drives in an array what with 16 to 32 bays now common place! Each drive is vibrating and those vibrations move in and out of phase with those of the other drives, sometimes creating harmonics that create sharply higher vibration forces. In many instances this problem was avoided by properly mounting the disk to limit these forces sufficiently. The problem now has been as densities continued to increase, even smaller vibrations could knock a read/write head off track.


This is where HGST’s rotational vibration sensors (RVS) takes vibration response a step further. Sensors on the edge of the drive sense incoming vibration and adjust the head position to vibrate in tune with external waves.

According to HGST: “Showing performance during vibration—is the most interesting. In the simulation, we shook the high-end machine so hard that, without RVS, it could only score 15% in our performance tests. However, the moment RVS was switched on, the score shot up to almost 70%. In the business machine, the improvement was just as significant, boosting performance from 30% to almost 90%.”


HGST makes a good case for its RVS technology, but then don’t be fooled as its competitors have similar solutions for RV, but this is an HGST product review and we’d rather stay focused and share with you what they are capable of delivering as far as technologies are concerned. These then are the two primary factors that one needs to consider when comparing NAS drives to Enterprise drives.

Aside from performance tests we need to look at the design aspects of both the 5TB and 6TB drives. The 5TB and 6TB drives are a five platter design and sport the SATA 6Gb/s interface with a Max areal density of 703 for the 6TB and 586 for the 5TB, spinning at 7200rpm with a 128MB cache buffer and an MTBF of one million hrs. It’s no mean feat. Not bad at all when you consider the 4TB equivalent has a street price of around $194.00, and hopefully the 5TB and 6TB will be relatively priced.

As previously mentioned both drives have Rotational Vibration Sensor support allowing for optimal reliability in RAID based arrays. HGST does classify the drives as a 24×7 availability which may signify their confidence in the drives. We recommend sticking to our selection method of how to choose between a NAS and enterprise drive for your next NAS array.

The previous 4TB drives we looked at came in a retail kit, and the 5TB and 6TB HGST will be offered in a retail box as well. Users wishing to buy drives for upgrades should be pleased to hear as its best sticking with retail kits when you are buying to upgrade. As far as NAS arrays go as long as the drive model numbers match for compatibility it will not make a huge difference if its retail or bulk when used for integration purposes.

Normally when searching for a drive we hear all sorts of myths and rumors about how, why and what to buy, seems to be part and parcel of our lives, so best to steer away from too many forums. A vast number of permutations effect the integration and reliability of drives, along with environmental ones such as handling bare drives, often the most neglected aspect of installing drives. I recall seeing a person remove a drive from its anti-static bag, clutching the PCB and then walking across room and discharging the PCB with the static he produced then being completely shocked when he discovered the drive would not work and was a DOA!


We have arrived at the section that everyone awaits with abated breath – Performance.

Sadly whilst performance does play a large part normally, for hard disk drives the pinnacle has to be the importance of reliability and longevity, as they are the most important piece of the NAS puzzle.

Performance measurements for this review will break from convention and also report on how the drives adapted to a few NAS arrays and by the time this review is published it will probably be a week to ten days from the time we received the drives so we can also measure short term effects of reliability and compatibility.

We decided to keep the performance testing simple and use standard hard disk drive testing utilities for this test. Naturally as HGST is now a Western Digital company we opted to get the WD RED drives for HGST NAS drives to pair with for testing. The RED drives we used are the standard and not the new PRO version; once again we could not get anyone at WD to talk with us for trying to get the PRO series for this review.


The Sequential Read Speed for the 5TB category shows HGST 5TB NAS drives doing reasonably well and edging the WD RED 5TB NAS drive, might have been nice to have the PRO series as it may have proved to be a worthy opponent.

HGST shows a consistent burst in speed, except for a slight anomaly at the 3.5GB to 4.00GB level when it’s hit with a downward spike in performance – somewhat strange – let’s not forget these drives come with pre-production firmware so we need to compensate for anomalies. The testing method utility does not support 128MB cache but only 64MB cache and as a result anomalies can and will occur when testing drives for burst speeds.


The performance differential is more evident in the 6TB category where the HGST Deskstar NAS is >25% faster than the WD Red. The seek time for Deskstar NAS was 9.5ms vs 12.2ms for WD Red. The Deskstar NAS continues to outperform WD Red even on burst speeds which measures the performance of the onboard cache.


In the secondary read, write tests we carried out it clearly seems the HGST NAS drives are streets ahead and this can mostly be attributed to the 128MB cache as well as the 7200rpm, this was similar to the results we had in the 5TB category as well. The only problem we saw was with the write result in the 4K and 4K QD32 in which the WD RED drive goes into overdrive. Again need to cognizant of the HGST with its pre-production firmware.

Both the HGST Deskstar 5TB and 6TB NAS drives were integrated in the NAS servers listed, set with RAID level 5 and commissioned to run our I/O data read, write software utility to ensure compatibility.

NOTE: Due to time constraints we were not able to use our NAS Compatibility test utility as the complete process takes over five days to perform per drive.



Apart from waiting to get pricing information from HGST, we are struggling to find a reason not to recommend HGST NAS 5TB and 6TB drives as a suitable companions for NAS servers. The HGST NAS drives ran hotter than the WD NAS drives – not a lot but definitely warmer, about six degrees or so higher.

Despite the fact that the HGST 5TB and 6TB Deskstar NAS drives were pre-production firmware, we remained impressed.

Our emphasis on using high quality drives for NAS servers is more prominent now than ever before, what with frequency of product announcements of higher capacity drives from various manufacturers.

For us drives are the cornerstone of storage and for someone like me it’s a matter of paramount importance to protect my information, and the thought of losing all or even part of it would be like losing a part of my life. Are you as passionate about your data?

Full HGST Product range –  http://www.hgst.com/hard-drives/internal-drive-kits/nas-desktop-drive-kit

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