WD Blue SN550: Notes on new versions with lower TLC write rates


With its good price-performance ratio, the NVMe SSD WD Blue SN550 (test) is popular and a recommendation from the editors. But this could change, because from Asia there are indications of a new variant with a different memory whose write performance in TLC operation outside of SLC mode & apos; is significantly lower.

WD Blue SN550 in new version

The Chinese website Expreview put it to the test after receiving information about a new version of the WD Blue SN550 and bought a new SN550. The 1 TB model with the date of manufacture July 28 has different memory chips: Instead of the previous identifier 60523 1T00, the modules are labeled with 002031 1T00. The firmware with 233010WD is now different from that of the old version (211070WD).

WD Blue SN550 in new version (Image: Expreview)

Write rate significantly decreased after the cache

Tests show that the new variant still achieves the 1,950 MB/s promised by the manufacturer in sequential writing and even exceeds it with 2,160 MB/s. However, the write performance after the SLC mode, which has a capacity of 12 GB when empty (cells are written with 1 bit), is only 390 MB/s. The sister series SanDisk Extreme, which is identical to the SN550, achieves almost 850 MB/s in TLC operation in the 1 TB version, according to Expreview.

WD Blue SN550 in a new version (Image: Expreview)

In other tests, at least over 600 MB/s were achieved with the old version. ComputerBase had tested the variant with 2 TB, which achieved around 750 MB/s after the cache, but is not comparable with the 1 TB model.

The write rate according to the cache as well as the first digits of the firmware version match the WD Green SN350, it is noted in the report. The fact that similar components are now used as in the entry-level model, which is one class lower, is an obvious assumption.

The editorial team has contacted Western Digital to clarify whether this new variant is also being sold in this country. It is also unclear whether customers can already see before they buy whether it is the new or the old variant.

Meanwhile there are already hints (again from Asia) that the new version of the 500 GB version also works more slowly in TLC mode. Just days ago, Crucial drew attention to itself with the switch from TLC to QLC in the P2 series.

The editorial team thanks community member “deo” for pointing this out this news.