The new Synology DS1823xs+ (and should you buy it over the DS1821+)


Synology has just come out with the DS1823xs+ which has an MSRP of $1,800. I am guessing that this unit is going to be pretty much replace the DS1621xs+, which I think makes a ton more sense. If you are going to go for an XS unit you might as well get 8 bays rather than 6.

The big question with this is, should you buy the DS1823xs+ over the DS1821+.



When it comes to networking the DS1823xs+ is pretty well loaded with:

  • 2x 1GbE ethernet ports
  • 1x 10GbE ethernet port
  • 1x Out of Band management port
  • A PCIe slot that can be used for up to 25GbE SFP28 networking

This pretty much should be all of the networking that someone needs! The out of band management port probably is going to get overlooked by most users, as this is a desktop unit, not a rackmount unit, but still really nice to see it!


The DS1823xs+ comes with 1x 8 gig DIMM of ECC DDR4 RAM, which should be more than enough for anyone just looking to use this as a NAS, but is upgradeable to 32 gigs. This is mostly useful for people looking to either run a lot of virtual machines / docker containers, or have tons of security cameras.

The CPU is a AMD Ryzen V1780B, which has gotten a pretty huge speed upgrade compared to the DS1821+. This speed will give real results for people using it with larger deployments, or looking to use it with 25GbE netowkring.

Hard drives and NVMe’s

The DS1823xs+ comes with 8x hard drive slots, that are only ‘compatible’ with Synology’s price hard drives. You technically can put any hard drives (or SSD’s) in this unit and it will let you build a volume, but the volume will constantly be in ‘warning’. This is a change up from Synology’s history of only having the requed drives on units with more than 8 bays. But this is listed as an XS+ unit, which likely is their rational.

This likely is the largest downside of this unit, other than the price


So as with all Synology XS/XS+ units the DS1823xs+ does not support Synology Hybrid Raid (SHR). This is due to the fact that with mix-matched drive sizes, SHR can give you non consistent performance, something not acceptable to the XS+ units.

The DS1823xs+ vs the DS1821+

If price is no objective the DS1823xs+ is a superior unit in pretty much every way. However price does matter. If you include the extra cost associated with the Synology Hard Drives vs standard drives, a fully loaded DS1823xs+ probably will be 2x the cost of an equivalent DS1821+. With this it makes it a really hard sell.

One thing that the DS1823xs+ really has going for it is the significantly faster CPU. Everything else that the DS1823xs+ has over the DS1821+ can be upgraded (Networking and RAM). (Well also the out of band management port most people are not going to use).

What do you think?

I probably would recommend to most clients the DS1821+ still today, but if you really are looking for the most powerful unit the DS1823xs+ does at least have some stuff going for it! I am glad that they upgraded the DS1621xs+ to being an 8 bay, as I really think that makes more sense. One thing that I am worried about is if they will totally drop the DS1823+ lineup. This would be very unfortunate.

Affiliate links:

1 Like

I think you summed up the pros and cons very well. The DS1821+ will probably see an upgrade in 2024 and will remain a popular device.

The DS1823xs+ is for a different segment of the market where performance and stability requirements make up for the higher price tag.

We just bought some DS1823xs+ for 2 very specific use cases and we so far we are very happy.

  1. Plattform for ActiveBackupForBusiness
  2. Synology HighAvailability Cluster

Plattform for ActiveBackupForBusiness (5* Seagte Exos 16TB + 32GB Non-Synology EEC RAM)
ABB is already a very nive application for backup. But what really makes this software an excellent choice for small office environments is the possiblity to verify the backup. This is done by booting the backup in VirtualMachineManager VMM. Success/Filure to boot will be communicated through the backup notification service.
We take hourly backups of 5-8 VM on 2 physical server (PDC, SQL Server, Print Servers, File Servers,…) and can boot them on the 1823xs+ without problems. The hardware is beefy enough to boot the VMs to the login-screen within our specified time windown of 4min. → Perfect plattform so far

HA Cluster
If you want to run a HA cluster the heat beat must be through the fastest network interface. In order to run the cluster with a 10G backbone you need an PCIe expansion slot. TMK this eliminates all models below DS1621.
But if you are already considering HA plattforms the price comparission is not so much DS1823xs+ vs DS1621 but more Synology vs DELL/HP/…
We still ran the NAS unsupported SEAGATE EXOS drives using the usuall scripts and it just works as a charm. We think we have enough fall-back layers that we shouldn’t be naked if the unsupoprted drives were to create problems.
If we were to invest into SSD we would definetly buy the Synology SSD as the TBW are excellent and similar business SSD are in the same cost bracket.

For a total investment budget of 4-5k USD of a HA solution the DS1823xs+ was a cheaper mix of [price/performance/software/license cost] against a HA Windows/Linus cluster. Especially if you consider that ABB and VMM come along free of additional cost.

Those are the two on my list, if I go the Synology route. My plan was to fill all the slots with 4 TB SATA SSDs, probably Samsung 870 EVO, RAID6, and also buy a dual 10GbE SFP+ card. So I could go with the xs+ right away, though I’d have to live with the drive warning, but I’ve decided to wait for the successor to the 1821+, and see how the specs are. Main reason: I’m still hoping for a return of integrated graphics. (And 64 GB RAM wouldn’t be too shabby either. :laughing:)

Why Raid6?

You only need the 2nd parity disk for the time it nees to rebuild the raid.
Since the disk is 4TB in size and with the raid system maxing out the write speed on the replacement drive the rebuild should be very quick - only some few hours.


To me it seems that the better option would be to go with Raid5 (supposedly faster) and just add the last SSD disk as hot spare (and therefore reduce the write operation of this drive resulting in a longer life time) or to keep it on the shelf and just add it when need one of the SSD drives starts to show warnings.

Also, since you should have a 3-2-1 backup in place anyway, just use a big HDD for local snapshot replication and you have your 1st layer. With immutable snapshots featured in DMS 7.2 the HDD could also be your safeguard against ransomware. Different to SSD a HDD usually does not fail in discrete mode [ok/instantly faulty] but slowly degrades which agives you a window of opportunity.

Solution for a tight budget (6 SSD, 1 HDD, 1*empty slot) that works initially with a single big HDD:**

Once the HDD#1 starts to throw SMART errors, you can add another big HDD#2 to make a HDD raid1 and then replace the failing HDD#1 with another big HDD#3. (rebuilding a raid1 with 2*seagate exos 16TB (80% full, warnings turned off through script) on our DS1823xs+ takes <10 hours) .

To this you need to add the time to procure the HDD#2 (1-2 days). So for 2-3 days your 1st level of backup has issues (but is very likely still functional). If level 1 was down you still have level 2 & 3 - so not a real issue if you closely monitor your system(s).

1 Like

Completely agree with you! RAID6 is very rarely if ever useful on SSDs!

Thank you for the info. :pray: I thought that RAID5 was only safe for fast SSDs (PCIe M.2), not for SATA SSDs. More options! Nice.

So I love that Amazon lists the ds1821+’s tech specs as:


45"D x 5"W x 100"H

So the unit is less than half a foot wide, nearly 4 feet deep and over 8 feet high :joy::face_with_peeking_eye::hugs::stuck_out_tongue_closed_eyes::melting_face::fist_right::fist_left: