Samsung PM1733 and PM1733a: Capacities, DWPD, Gen 4 Speed and UK Prices

Samsung PM1733 specifications: PCIe 4.0 NVMe in a U.2 body

Samsung's PM1733 product brief, which carries a 2020 copyright, is the main source on this page. It lists the form factor as U.2 / 2.5 inch, the host interface as PCIe Gen 3/4 x4, and compliance with NVMe 1.3 and the PCI Express base specification 4.0. Because the brief gives separate figures for Gen 3 and Gen 4 hosts, the speed you get depends on the server as well as the drive.

Reads gain most from Gen 4: sequential read doubles and random read nearly doubles, while sequential write moves only from 3,200 to 3,500 MB/s and random write does not change. A write-heavy server on Gen 3 loses little on these figures; a read-heavy one loses half its sequential read.

• Dimensions 69 x 100 x 15 mm.
• Power, active and idle: 20 W and 8.5 W.
• MTBF 2,000,000 hours.
• Endurance 1 DWPD for 5 years in the capacity-optimised set-up.
• Encryption: TCG Opal 2.0.

Samsung PM1733 3.84TB, 15.36TB and the 3 DWPD sizes

The brief describes two set-ups of the same drive. As shipped it is capacity-optimised, at 1 DWPD in 1.92TB, 3.84TB, 7.68TB and 15.36TB. Samsung says it can alternatively be reconfigured for endurance and performance, at 3 DWPD in 1.6TB, 3.2TB, 6.4TB and 12.8TB, and that the firmware can be modified by the user to exchange some capacity for additional endurance. The brief's highlights give the overall range as 1.6TB to 15.36TB.

The daily figures are our arithmetic, capacity times DWPD, not a Samsung table. On them the 3 DWPD set-up gives up about a sixth of the capacity for two and a half times the daily writes. Because the change is a firmware one made by the user, a used drive could be in either set-up: if a listing names a 3.2TB or 6.4TB PM1733, ask the seller which set-up the drive is in and what capacity it reports.

Samsung PM1733 vs PM1733a

Samsung's PM1743 white paper carries a Gen 4 table that sets the PM1743, PM1733a and PM1733 side by side, at the same four capacities from 1.92TB to 15.36TB, all PCIe Gen4 and all 2.5-inch, 15 mm thick. Four of its rows separate the PM1733a from the PM1733, and on each the PM1733a is level or ahead.

The paper prints the sequential unit as Mbps, so we give its numbers as printed. The biggest gap is at 1.92TB, where the PM1733a's random read is 1,400K IOPS against 800K. Above that size the two are close, and they match on random write from 3.84TB up.

The two Samsung documents do not give the PM1733 identical figures: the 2020 brief lists 3,500 MB/s sequential write on Gen 4, while the white paper's table prints 3,800 from 3.84TB up. We show each figure with its own document rather than choosing between them. We have not found a Samsung data sheet for the PM1733a, so we print no power or endurance figure for it; do not read the brief's figures across to it.

Samsung PM1733 and PM1733a at 30.72 TB: what the documents say

The 30.72TB size rests on one line. It is stated in the summary description of a Samsung web page that covers both the PM1733 and the PM1735: capacities up to 30.72TB. That line names the PM1733, not the PM1733a, and pairs 2.5-inch with HHHL, a shape the brief does not list. The 2020 brief stops at 15.36TB, and the white paper's table also runs from 1.92TB to 15.36TB.

We have not found a Samsung document giving a 30.72TB part number, its endurance or its speed. A listing that offers a PM1733 or PM1733a at 30.72 TB asks you to trust a figure that cannot be checked against a sheet, so ask the seller for the full model string and a Samsung document that covers it.

Dual port, power loss protection and virtual drives

Samsung says the PM1733 supports dual-port functionality, enabling high availability through two access paths to the storage array controller. Whether a server uses the second path depends on its backplane, so check that in the server's own documents.

On power loss, the brief says that when a failure is detected the SSD uses stored energy from tantalum capacitors to give enough time to move cached data from DRAM to flash, so no data is lost. That is a maker's description of the mechanism, which is more than a bare yes in a feature list.

The brief also says Samsung's SSD virtualisation lets each PM1733 be divided into 64 separate virtual drives. Encryption support is TCG Opal 2.0.

Fitting a Samsung PM1733: the 15 mm U.2 bay

At 15 mm thick, the PM1733 needs a bay that takes a 15 mm 2.5-inch drive, and a slot wired for NVMe over U.2. Check the form factor, the interface and the drive height in your server's own documents. On a Gen 3 host the brief's Gen 3 column applies, so the drive is not wasted there, but its sequential read is half the Gen 4 figure.

Samsung PM1733 price on Amazon.co.uk

The table holds no listings right now. Prices are pounds sterling inc VAT, sorted per TB, and each row shows its condition. The table takes Samsung titles naming the PM1733 and leaves out the PM9A3, PM1743 and PM1735. We have not found a Samsung part-number list for the PM1733 or PM1733a, so match the capacity against the lists above and ask the seller for the model string before you press Buy on Amazon.

The Samsung PM1743 page covers the PCIe 5.0 drive in the same white paper, and the U.2 SSD page explains the connector and drive heights. For the sizes themselves, the 3.84TB SSD and 15.36TB SSD pages compare drives across makers.

In-stock alternatives

None of these is the product this page covers: they are what is in stock on Amazon.co.uk beside it right now. Each row says why it is listed. Check the interface, form factor and part number against your system before buying.