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Be careful with the SSD you buy: Samsung, Crucial and WD are selling units with worse performance without warning

You are updating your PC and you buy a brand new SSD drive in M.2 format. Let’s say a Crucial P2. Or a Samsung 970 EVO Plus. Or a WD Blue SN550. You’re happy until you realize that these units, which should go like a shot, they go much slower than you expected. Are they defective?

No. What happens is that the manufacturers they are starting to integrate worse chips in these units, and they are doing it without warning. Various reviews demonstrate how some units from Samsung, WD, and Crucial have performances that are as low as a quarter of those offered with the original chips, and these manufacturers have not warned their users of this problem.

From TLC chips to QLC and I throw because it’s my turn

One of the first to be discovered doing this type of practice was Crucial, a well-known manufacturer part of Micron that had an excellent option in its Crucial P2 units for many users.


Which is which? Source: Tom’s Hardware

Suddenly Crucial started selling Crucial P2 drives that instead of using TLC memory chips, more capable and with better performance, began to use QLC chips, slower and with less durability.


The one at the bottom, with the fewest chips, is the “bad” one. Each QLC chip allows more data to be stored, but performance suffers dramatically. Source: Tom’s Hardware.

Tests carried out on some media show that the Crucial P2 SSD with QLC chips is up to four times slower than the original model with TLC chips: read speeds drop by half, and write speeds suffer the most and according to Tom’s Hardware they do not exceed just 40 MBps in one of the tests when the normal model hovered around a respectable 450 MBps.

There was also no easy way to distinguish a model with QLC chips from one with TLC chips except for the fact that in the model with TLC chips the unit simply has fewer memory chips because each QLC NAND chip stores more data and that makes it possible to reduce the number of chips involved: Crucial saves money with this, they assure in Tom’s Hardware.

There are other manufacturers that have been caught with this type of practice: Samsung has apparently done the same with its 970 EVO Plus units, and in an independent analysis on YouTube, one user found that write rate performance dropped from 1,500MB / s to 800MB / s, almost half.


More trouble identifying a “bad” SSD versus its original version.

In ExtremeTech they indicated how despite being two theoretically different units, the model codes that identified them were different: The “good and old” was the MZVLB1T0HBLR, while the “new and worse” was the MZVL21T0HBLU.

If you remove the sticker from the bottom chips, you can see more differences – the chips are still TLC, but underperforming – and although the differences are not as dramatic as those in the Crucial case, the performance remains lower and again, as in the previous case, Samsung has not said a peep about that change.

At Western Digital, more of the same. Your WD Blue SN550 unit has swapped TLC NAND chips for QLC NAND chips and, as in the case of Crucial, performance impact is noticeable especially in writing rates and if the available cache runs out.

In those cases the performance may fall about halfAbout 390MB / s for new drives with QLC chips versus 610MB / s for original drives based on Expreview reviews.

Another of those who seem to have resorted to these measures is Adata, whose XPG SG8200 Pro drive it also appears to have lost much of its performance in its latest reviews.

Only WD has admitted it, but that doesn’t do much good

At Engadget we have tried to contact those responsible for Samsung, Crucial and Western Digital, but only the latter have responded to the complaints with the following official statement:

“In June 2021, we replaced the WD Blue SN550 NVMe SSD NAND and updated the firmware. At that time, we updated the product data sheet. For future transparency, if we make a change to an existing internal SSD “We are committed to introducing a new model number whenever related published specifications are affected. We value our customers and are committed to providing the best possible solutions for their data storage needs.”

“For any WD Blue SN550 NVMe SSD with the new configuration that is under warranty but does not meet performance requirements, customers can contact our Customer Care team for assistance with replacement.”

At WD they apparently offer “replacement” for the drive, but the problem is that neither they nor the rest of the manufacturers mentioned such a strategy when they applied it. They did not warn their customers and users, and that can end up representing a problem for many.


WD already had a lot of criticism with its SMR NAS drives, and now the problem is repeated with its SSDs.

It also doesn’t help to know that manufacturers like himself WD already did something similar with their WD Red drives, which are theoretically perfect for NAS but used in its new models an SMR technology that was clearly inferior to the PMR / CMR used in drives traditionally used in network hard drives. Once again WD did not advise of the change and only acted on the issue when the issue was discovered in the media.

Neither Samsung nor Crucial have responded for the moment to our requests for clarification, but in the absence of such clarification these movements could be aimed at cutting production costs.

Said cuts could well 1) be reflected in the sale prices – some of these units may be somewhat cheaper than before, of course – and that above all 2) they should have been sold with a clear warning that performance could be impaired in these models compared to the originals.