Reviewing the Synology DS1817+ with M2D17

The M.2 SSDs

The SSD read-write cache feature requires two SSDs in RAID 1 configuration. Hence, we gotten two different but similar capacity M.2 SSDs, namely:

  1. Samsung 850 Evo 250GB
  2. Western Digital Blue 250GB

What are the pros and/ or cons of using different SSDs?

  • Pro. Don’t suffer from concurrent failures due to design flaws.
  • Con. Degraded RAID 1 performance if SSDs have different performance

Why are the SSDs configured in RAID 1 in a read-write cache? The cache is the first location to fetch or deposit your data and it will reach out to the regular disks if the desired contents cannot be located in the cache. For write caching, any failure in the cache storage will result in data loss and thus RAID 1 is required to protect written data. On the other hand for read caching, the data are still available in the regular disks thus RAID 1 is not required.

 

Samsung 850 EVO 250GB M.2 SSD

Samsung 850 EVO 250GB M.2 2280 SSD for DS1817+’s read-write SSD cache!

Samsung 850 EVO 250GB M.2 SSD Specifications
Controller Samsung MGX
Interface SATA 6GB/s
Memory Samsung V-NAND
Cache Memory 512 MB Low Power DDR3
Sequential Read Up to 540 MB/s
Sequential Write Up to 520 MB/s
Random Read (4KB, QD32) 97,000 IOPS
Random Write (4KB, QD32) Up to 89,000 IOPS
Warranty 5 Years or 75 TBW

Samsung 850 EVO 250GB M.2 2280 SSD for DS1817+’s read-write SSD cache!

 

Western Digital Blue 250GB M.2 SSD

Western Digital Blue 250GB M.2 2280 SSD for DS1817+’s read-write SSD cache!

WD Blue 250GB M.2 SSD Specifications
Controller Marvell 88SS1074
Interface SATA 6GB/s
Memory SanDisk 15nm TLC
Cache Memory 256 MB Low Power DDR3
Sequential Read Up to 540 MB/s
Sequential Write Up to 500 MB/s
Random Read (4KB, QD32) 97,000 IOPS
Random Write (4KB, QD32) Up to 79,000 IOPS
Warranty 3 years or 100 TBW

Western Digital Blue 250GB M.2 2280 SSD for DS1817+’s read-write SSD cache!

 

Side-by-side comparison of Samsung 850 EVO and WD Blue

Samsung 850 EVO WD Blue
Controller Samsung MGX Marvell 88SS1074
Interface SATA 6GB/s
Memory Samsung V-NAND SanDisk 15nm TLC
Cache Memory 512 MB Low Power DDR3 256 MB Low Power DDR3
Sequential Read Up to 540 MB/s
Sequential Write Up to 520 MB/s Up to 500 MB/s
Random Read (4KB, QD32) 97,000 IOPS
Random Write (4KB, QD32) Up to 89,000 IOPS Up to 79,000 IOPS
Warranty 5 Years or 75 TBW 3 Years or 100 TBW

At this juncture, both SSDs’ performance looks great. In the later part of this review, we will be benchmarking their performance under some synthetic workload.

4 thoughts on “Reviewing the Synology DS1817+ with M2D17

  • July 28, 2017 at 11:16 am
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    drool ~~~~

  • August 31, 2017 at 4:23 am
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    i’ve been looking at upgraded NAS offerings. this seems like a great choice, my workflows are mostly IOPS limited, so this would represent a significant increase in performance and a significant decrease in keyboard smashing stress.

  • January 10, 2018 at 10:50 am
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    Good review. Do you know if it possible to use an M.2 SSD installed in the M2D17 card as an extra storage device? Such as using it to run all your app’s etc (docker, virtual machines…) instead of running them off the array. I currently use slot 8 with an SSD installed for this purpose

  • January 10, 2018 at 12:32 pm
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    Hi Darren,

    Unfortunately, we can’t use the SSD on the M2D17 as storage volume. It will just appear as SSD cache.

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