No. The TS-453E is a diskless enclosure — the four bays ship empty and the price is for the unit alone. It takes 3.5-inch SATA hard drives or 2.5-inch SATA SSDs, up to four of them. Check any drive against QNAP’s compatibility list first, because not every model on the market is validated for NAS duty. Tell us the usable capacity you are after and the RAID level you want, and we will quote the drives with the unit.

That depends entirely on the drives and the RAID level, which is why we will not print a headline capacity. As a guide with four identical drives: RAID 5 gives you three drives’ worth and survives one failure; RAID 6 gives you two drives’ worth and survives two; RAID 10 gives you two drives’ worth with the best rebuild behaviour. The storage pool tops out at 308 TB and a single volume at 250 TB, so the drives will be your limit long before the software is.

QTS is the standard QNAP operating system and what the TS-453E runs out of the box. QuTS hero swaps the file system for ZFS, which adds end-to-end data integrity checking, inline deduplication and WORM for tamper-proof retention. This model can run either — you can switch to QuTS hero from QTS 5.2.1 onwards. QuTS hero is hungrier for memory, so if you plan on it, budget for the second 8 GB module at the same time.

You can. There are two SODIMM DDR4 slots with one 8 GB module fitted, for a 16 GB maximum. QNAP is unusually blunt about modules: it states that using unsupported memory may degrade performance, cause errors or stop the operating system starting, and that multi-slot systems should use identical QNAP modules. We would follow that rather than fit a third-party stick to save a little.