How much storage fits in the QNAP TS-233?
By Devin Chua · Data checked by Owen Nakamura · Updated · Prices checked The QNAP TS-233 takes 2 drives, but usable is the number that matters: 2 × 8 TB in RAID 1 gives 7.28 TiB for about CA$1,144 in drives, and it survives 1 drive failing. The gap from raw capacity is parity.
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Want to know whether the TS-233 fits your actual storage plan? Open the NAS Builder with this model weighted.
Usable space in the TS-233, by drive size
All 2 bays filled with equal drives in RAID 1, the TS-233’s sensible default. Usable TiB is what the NAS reports; TB is the drive maker’s unit.
| Drive size | Raw | Usable (TB) | Usable (TiB) | Drive failures survived |
|---|---|---|---|---|
| 2 × 4 TB | 8 TB | 4 TB | 3.64 TiB | 1 |
| 2 × 8 TB | 16 TB | 8 TB | 7.28 TiB | 1 |
| 2 × 12 TB | 24 TB | 12 TB | 10.91 TiB | 1 |
| 2 × 16 TB | 32 TB | 16 TB | 14.55 TiB | 1 |
| 2 × 20 TB | 40 TB | 20 TB | 18.19 TiB | 1 |
| 2 × 24 TB | 48 TB | 24 TB | 21.83 TiB | 1 |
How much space you actually need
Start from what you store today, not from the drive sizes. As rough guides: a 24-megapixel RAW photo is about 25 to 30 MB, a phone photo 3 to 5 MB, and an hour of 4K phone video around 20 GB; check a folder of your own files for real numbers. Add the growth you expect over the next three to five years, then keep about 20 percent free so the pool does not run full.
Then plan the backup copy. RAID keeps the TS-233 running through a drive failure; it does not protect against deletion, ransomware, theft or fire. Size a second copy (an external drive, a second NAS or a cloud plan) for the data you cannot replace, which is often far less than the array.
For your own mix of drive sizes and RAID types, use the TS-233 capacity calculator. For drives that fit and their current Amazon.ca prices, see the best drives for the TS-233.
A worked configuration for the TS-233
WD Red Pro or Seagate IronWolf Pro in every bay is the recommendation for the TS-233. At 2 × 8 TB in RAID 1, the TS-233 lands 7.28 TiB usable for about CA$1,144 in drives, gives up 8 TB to parity, and survives 1 drive failing. Step the same 2 bays of the TS-233 up to 16 TB drives and it holds roughly twice that, at the CA$/TB the live table above shows.
One rule holds on every NAS, the TS-233 included: use CMR drives, not SMR. SMR drives rewrite overlapping tracks and collapse during a RAID rebuild, dragging a repair from hours into days.
Drive policy: QNAP locks no drive brand on the TS-233; its compatibility list is guidance, not a gate. The TS-233’s full compatibility rules.
Keep calculating
To see how much capacity is left after parity, the TS-233 capacity calculator is preset to its 2 bays and RAID types. For the TS-233, the wider basics of choosing a drive are in the buying guides, and CMR versus SMR explains why SMR drives do not belong in a RAID array. Wondering what the TS-233 can actually do: Plex, Immich, Docker, VMs? See what the TS-233 can run.
Frequently asked questions
What is the maximum storage in the TS-233?
2 drives. QNAP publishes no raw-capacity ceiling for the TS-233; the compatibility list governs.
How much of the TS-233 is actually usable?
In the TS-233, 2 × 8 TB in RAID 1 yields about 7.28 TiB: that is 8 TB in drive-maker terms, with 8 TB to parity. It shows less than the label because it counts in powers of two.
Can I fit larger drives in the TS-233 later?
Yes, but on the TS-233 classic RAID sizes to the smallest drive, so the extra space arrives only once every drive is replaced. There is no flexible RAID like SHR on this model.
Can I put third-party drives in the TS-233?
Yes. QNAP locks no drive brand on the TS-233; its compatibility list is guidance, not a gate.
Devin Chua works out which drives, RAM and NVMe cache fit which NAS model at nasdrives.ca, and what the RAID choice means for usable capacity, checked against what is in stock on Amazon.ca.
Data checked by Owen Nakamura, Technical editor (data checking)