Synology DS124 Specs and Usable Capacity

Published specifications for the Synology DS124, a 2023 model, together with the number the manufacturer page will not give you: how much usable capacity you actually get from 1 bay under each storage layout, at every drive size worth buying. A single-bay DSM box. One drive means no redundancy at all, so it belongs on the network as a backup destination rather than as the only copy of anything.

Synology DS124 specifications

Specifications come from manufacturer published data. Vendors sometimes ship the same model number with different memory fitted or drives included, so confirm against the listing for the exact unit you are buying. Where a figure is not published, the row is omitted rather than estimated.

How much usable storage does the DS124 actually give you?

Raw capacity is bays multiplied by drive size. Usable capacity is what survives after parity, and it is always a whole number of drives smaller. Every figure below is computed from 1 identical drives using the same engine behind our cross-vendor RAID capacity calculator, so you can check it.

All capacities are decimal terabytes, the unit printed on the drive label. Your NAS interface will report binary tebibytes and label them "TB", which makes every figure look about 9.05 percent smaller. Nothing is missing: one TB is 1,000,000,000,000 bytes and one TiB is 1,099,511,627,776, so the ratio is a fixed 0.909495. See the TB against TiB chart for the conversion at every capacity, and expect the filesystem to take a further one to two percent on top.

What drives should you put in a DS124?

The enclosure is the cheap part. 1 drive at $200 to $500 each is a $400 to $1,000 purchase, and unlike the box the drives get replaced and upgraded over the life of the array. Two requirements are not negotiable: CMR recording, never SMR, because shingled drives can take days to rebuild an array, and a published NAS workload rating of at least 180 TB per year.

Buy all the drives at once if you can afford it, so they age together and you know their history. Buying them from different retailers or in two batches is a cheap way to avoid every drive coming from the same manufacturing run. See our NAS drive comparison for the full field and how to choose NAS drives for the reasoning.

What are the real limits of a 1 bay NAS?

A single-bay NAS has no redundancy of any kind. There is no parity, no mirror and nothing to rebuild from, so when the drive fails everything on it is gone. Mechanical drives fail at roughly 1.0 to 1.6 percent per year across large fleets and the rate rises past about five years of service, which makes this a question of when rather than whether over the life of the unit.

That is not a reason to avoid one. It is a reason to be honest about the job. A single-bay unit is an excellent destination for laptop backups and for a nightly copy of data that already lives elsewhere. In 3-2-1 terms it is copy two, and copy two is allowed to be unprotected precisely because copies one and three exist. The 3-2-1 backup guide covers what the other two copies have to be, and the backup sizing calculator will tell you how much capacity you actually need.

Do not make this the only home for anything. If the only copy of your photographs sits on a single unprotected spindle, you have bought a countdown rather than a backup. Two bays is the smallest configuration that survives a drive failure, and it costs one more drive.

The other limit worth knowing is growth. There is no expansion path at all: the only way to add capacity is to replace the drive with a larger one and copy everything across. If the data set is growing at any real rate, a two-bay or four-bay unit bought now is cheaper than this unit plus its replacement.

What does a complete DS124 build cost?

Every specification page for this unit stops at the enclosure price, which is the smaller half of the purchase. Filling 1 bay is 1 drive at $219.00 to $1,059.99 each, so the table below is the number that should actually decide the purchase. Box cost is the midpoint of the published Under $200 band, and drive prices are the verified listing prices from our drive comparison.

Box cost is an estimate from the published price band and the real listing moves, so treat the totals as the shape of the spend rather than a quote. Usable capacity is decimal TB computed for 1 identical drives, and your operating system reports it about 9.05 percent smaller in binary tebibytes. Totals exclude tax, shipping, a UPS and a backup target.

Read the last column. At 16 TB drives the 77 percent of this build that is drives is money you will spend again, because drives fail and get upgraded on a rolling schedule while the chassis does not. That is the argument for choosing the enclosure on the features you will genuinely use and then spending the remaining argument on capacity. The buying order guide works through the allocation, and the cost per terabyte chart shows where the sweet spot sits across the whole field.

Who the Synology DS124 suits

• A cheap second copy of data that already lives on a computer.
• Anyone who wants to learn DSM before committing to a multi-bay unit.
• Not suitable as primary storage, because a single drive has no fault tolerance of any kind.

What it costs to leave running

A NAS runs continuously, so the electricity bill is a real part of ownership. Budget roughly 6 to 9 watts per spinning drive at idle plus the enclosure itself, which for 1 drive lands somewhere around 16 watts idle once the drives have spun up. Put your own tariff and drive count into the power draw calculator for an annual cost, and size a battery with the UPS runtime calculator, because an unclean shutdown during a write is one of the few things that can damage an array rather than a drive.

What else does a DS124 build need?

Three things get left out of almost every plan at this stage, and all three are cheap relative to what has already been committed to drives.

• A UPS with a data cable. A NAS losing power part way through a write is one of the few events that damages an array rather than a drive, and a unit with no USB connection to the server is a delay rather than a protection: it holds the array up and then drops it mid-write anyway. Size the battery on the UPS runtime calculator, and note that you are sizing for a clean shutdown of 10 to 15 minutes rather than for riding out the outage. Picks are on best UPS for a NAS.
• A backup target. Whatever parity this box runs, the array is copy one. Parity rebuilds a failed drive and does nothing about accidental deletion, ransomware, a controller writing corruption to every member, theft or fire, because each of those reaches every drive in the chassis at once. Work out the capacity on the 3-2-1 backup sizing calculator.
• A network that can keep up. 1 x 1GbE is the published port configuration here. A gigabit link carries about 113 MB per second and a single 7200 rpm drive already sustains 150 to 260, so if this unit has multi-gigabit ports and your switch does not, you have paid for a link speed you never see. Check the arithmetic on the network throughput calculator.

Related reading

• Cross-vendor RAID capacity calculator, SHR against ZFS against standard RAID for the same drives
• Best NAS hard drives, where the money in this build actually goes
• RAID levels explained in plain language
• NAS against a DIY server, if you are still deciding
• All NAS model specifications