06 June 2016

Seagate ST8000VN0002 NAS drive Review

Seagate ST8000VN0002 NAS drive Review

Seagate ST8000VN0002 is not your normal desktop Hard Disk. It is a hard disk that is meant for a network access storage (NAS). As a NAS is the central data store for a small home office or the 'cloud' storage of family members, it is important that such data are readily backup in the form of a RAID array. In addition, the the HDD in question should have 24 x 7 realiability.

Some end users will say, why bother with a NAS drive, we could just use 2 x normal high capacity to do the daily backups. Normal HDD do have a lower mean time between failure (MTBF) which might not be suitable for such a task. You wouldn't want to keep swapping HDD every few months in order to keep the files in proper integrity.

NAS drive used to be slower in it's speed in terms of it's revolution per minute (RPM). Most of them should be rated at 5400 RPM and comes with a 64 MB cache. Seagate's NAS drive ST8000VN0002 features a 7200 RPM spindle speed, 256 MB DRAM cache with SATA 6Gbps interface. According to the specfications, it is said to be able to ustain at a maximum speed of 216 MB/s media to cache transfer rate.

It also has a MTBF of 1M hours which is closer to an enterprise class which usually rates it at 1.2M hours. In addition, Seagate NASworks technology improves the realibility by tuning drive features to deliver higher performance, superior reliability and inter operability with popular NAS enclosures. The drive comes with an optional 3 years +Rescue Data Recovery Service plan for peace of mind as it protects again data loss in any RAID environment such as human error or handling accident.

Spec Sheet

According the Spec. Sheet, the drive is supported on 1 to 8 bays and comes with Dual Plane Balance. It has a sustained transfer rate of 216 MB/s - a very impressive speed for a HDD.


How does this drive compare to existing HDD and NAS drives? First, we will check out it's performance of 216 MB/s is achievable.

We will first use our fastest desktop series WD VelociRaptor 1TB HDD WD1000DHTZ which has a 10K RPM to do a comparison using two benchmarks.

PC used is a Gigabyte Z97 motherboard with an Intel 4770K processor with 8GB on board DDR3-2400. The HDD are connected to the SATA 6Gbps port for the test.


The results are a pleasant surprise for me. A score of 239MB/s for read an 234.7 MB/s for write. That is even higher than the 216 MB/s spelt out in the spec sheet.

Although it runs at 7200 RPM versus the WD at 10000 RPM, it still exceeded the performance. in sequential read / write and even 4K tests.

ATTO Disk Benchmark

As for ATTO Disk Benchmark, the results clearly shows that at whether it is a small or bigger block transfers, the NAS drive from Seagate actually outperform the fastest 10K RPM HDD by almost 30% (64MB block).

The HDD are installed into the Synology DS213, a 2 Bay NAS with Gigabit Ethernet connection to the same PC directly. The Synology drive recognises the HDD and asked it to be initialised into the various configurations.

The default which is Synology Hybrid RAID was used to initialise the drives. After which, we have to install the DSM 6.0 downloaded from Synology website before we can begin in our tests.

We will be comparing the Seagate ST8000VN0002 with 2 Western Digital RED drives WD30EFRX in terms of performance in read write file transfer.

Using the Synology Assistant, we mapped the drive to Z:\. After which used the software TeraCopy to transfer the files (from Windows 10 installation USB stick ~ 3GB) to the NAS storage. TeraCopy will record the average transfer rate and time it took to do the transfer.

Next, we do the reverse, copying the folders from Z:\ back to the PC and record the TeraCopy transfer speed and time.

Below is a screen shot of TeraCopy followed by a chart showing the MB/s transfer rate.

In both read from and write to the NAS, the Seagate is faster than the WD30EFRX, this could be due to two factors, the faster RPM and secondly the larger cache.

Dark Green : Reading from NAS
Light Green : Writing to NAS


Next, we used DiskSpd, a command line utility to test the speeds of connected periperhals. It will test the speed, latency, I/O per sec etc based on samples generated. In this test, we used a mixture of 30% / 70 % of read / write.

The Block size is set to 8K and it will run for 60 secs with hardware and software caching turned off. There will be 2 overlapped IO and 4 threads per target with random 30% writes and 70% read with a 50MB test file.

Here are the results :

We can see from the results, the Seagate experience less latency during the tests. The lower the latency the better the transfer rate.

When we talk about I/O, the I/O per sec based on the test set is necessary to determine the performance of the target. In this case, both HDDs were tested under the same environment. It is very apparent that the higher the I/O per sec, the quicker it is. 

The difference is almost 20%.

The concurrent Read and Write (70/30) of the 50MB test file gave a more realistic representation of the actual transfer speeds in real world. 

Again, we see that the transfer rate of the Seagate is faster at 35.83 MB/s compared to 29.87 MB/s on the WD NAS drives.


HDD has always been the defacto mass storage media for data centres, NAS or PCs. As storage becomes larger, the more we should look for a HDD that has a higher MTBF and higher speed of transfer.

Seagate ST8000VN0002 seems to meet the requirements of today's NAS, with higher capacity of 8TB and 7200 RPM plus 256MB cache with faster speed than before.

Within the NAS enclosure, the ST8000VN0002 is a bit louder and warmer than the WD RED drives.  As we can see from the NAS management console, the temperature runs from 32 deg C to 42 deg Celsius idling for half an hour. The temperature should come down if the NAS is placed in a colder room.

For a similar price, the Seagate would be better value for money.
The Seagate ST8000VN0002 now retails at USD 375 on Amazon USA store. There is a shipping fee of $15.19 . On the other hand the closest rival 8TB from WD Red 8TB NAS 5400RPM WD80EFZX retails for $335.85.

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