Samsung seemingly caught swapping components in its 970 Evo Plus SSDs. What is samsung 970 evo plus

As we are looking at the smallest drive in the line, performance and endurance will naturally be weaker due to the way the controller channels are populated. Advertised specs are still very good.

Samsung seemingly caught swapping components in its 970 Evo Plus SSDs

Jim Salter – August 27, 2021 22:20 UTC

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Enlarge / There is no part number on the package, which distinguishes the newer, slower drive from the older, faster drive – check the PN box in the top center of the label on the disc itself.

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Recently, major SSD vendors Crucial and Western Digital have been caught replacing the TLC NAND in their consumer SSDs with cheaper but much lower performance and lower endurance QLC NAND. Samsung seems to be joining them today in an embarrassed parts swap corner, thanks to Chinese YouTuber 潮 玩 客 who documented the new version of the Samsung 970 Evo Plus using an inferior disk controller.

While the model number of the drives aimed at consumers has not changed – last year it was the 970 Evo Plus and now it is still the 970 Evo Plus – the manufacturer’s part number has changed. Unfortunately, the manufacturer’s part number isn’t visible on the box the SSD is in – as far as we’ve been able to determine, it’s only visible on a small label on the drive itself.

Falling off the write cliff

This CrystalDiskMark test makes the newer, inferior drive look faster than the original in most tests, but note the very small 1GiB test size. This test does not escape the SLC write cache!

In this HD Tune Pro test, we see a ‘write cliff’ effect on both drives when the SLC cache is depleted – but the difference is not that HD Tune Pro vs CrystalDiskMark is a 1GiB test vs a 200GiB test.

We can also see the “write cliff” effect in a simple copy of a large file – when the write cache runs out, the new drive is much slower than the old one.

Further Reading

We tested the 970 Evo Plus (along with the 980 and the older 970 Pro) in March, clocking it at a write speed of 1600+ MiB / s with a load of 1 MiB. Our benchmarks were performed on the old version, part number MZVLB1T0HBLR. The newer version – part number MZVL21T0HBLU – is much slower. According to the results of testing 潮 玩 客, the newer version only manages 830 MiB / s – half the size of the original.

It seems likely that Samsung, like Western Digital, hoped the part swap would go unnoticed as the end result was “good enough”. For most light workloads, the user may never notice the lower performance of the new part number – because, like almost all modern SSDs, the 970 Evo Plus comes with an SLC write cache which is significantly faster than its NAND main memory, and the performance degradation the new part becomes visible only after the cache is exhausted.

潮 玩 客 tested the old and new 970 Evo Plus drives for the first time with CrystalDiskMark, and the drives looked almost identical. But that’s because CrystalDiskMark uses a very small 1GiB test size by default, which is clearly not enough to exhaust each disk’s write cache. (We use CrystalDiskMark a lot at Ars – but that’s exactly why we choose larger test sizes.)

Over extended testing, performance of both drives drops sharply as the cache fills up, which is to be expected. But while the older drive retains nearly two-thirds of its original performance, the newer version shrinks to less than a third. We see this effect not only in artificial benchmarks, but also in large file copies, as seen in later 潮 玩 客 tests.

The Multilevel Cell (MLC) was a poorly composed moniker that was closely related to the 2-bit NAND memory. Additionally, the MLC can also be applied to other NAND types that store multiple bits per cell.

Samsung 970 EVO Plus 250GB Overview

The 970 EVO Plus 250 GB is available in a single-sided M.2 2280 (80 mm.

970 EVO Plus 250 GB Front

970 EVO Plus 250 GB Front

The front has all the standard information on the label. There are no heat spreaders or heat sinks.

970 EVO Plus 250 GB Back

970 EVO Plus 250 GB Back

The back is completely sterile except for the sticker. By excluding anything to the back of this drive, it’s generally easier to cool down as it doesn’t require a cooling solution to be placed between the SSD and the motherboard or M.2 PCB. Since these modules are not intended for servers, there is no power loss protection (PLP). You can read more about why PLP is important in certain server workloads in our article What is ZFS ZIL SLOG and what makes it good. This is case-specific, but includes some diagrams and an explanation of what happens to these disks when they have and do not have PLP.

Samsung Software Bundle

The 970 EVO Plus entitles the end user to download several programs from the Samsung website.

Samsung Data Migration

This tool is a fairly basic disk cloning application.

Samsung data migration

Samsung data migration

You select the disk you want to clone and the target disk, and this tool does the cloning.

Samsung Magician

Perhaps the more important application for daily operations is Samsung Magician.

Samsung Magician

Samsung Magician

This tool provides Samsung drive firmware updates, diagnostics, drive information, secure erase, and a performance test. If you really care about your stock, this is a good tool. At the same time, as long as you’re not trying to change something on the drive, such as updating the firmware, you don’t need to install it for the drive to work.

Samsung has introduced a wide range of SSDs, which also includes reliable NVMe SSDs. Both the SAMSUNG 970 EVO and SAMSUNG 970 EVO Plus are well-known NVMe SSDs in the market.

Storage Space

Samsung has introduced variants up to 2TB for the 970 EVO and 970 EVO Plus NVMe SSDs. Currently, you can get any of the 250GB, 500GB, 1TB, 2TB SSD variants listed.

Note: If you are going to buy an SSD with an effective read / write speed, 2TB is your best choice. The higher variant includes an impressive R / W speed. Before that, when investing in any NVMe SSDs, consider the actual need, and then move on to make a purchase.

Sequential Read/Write Speed (Theoretical)

The company says these speeds are achieved with Samsung’s TurboWrite technology.

Read/Write Speed of SAMSUNG 970 EVO NVMe SSD

The read speed for 250GB / 500GB / 1TB is the same as 3,400MB / s, while the 2TB variant includes a better read speed of 3,500MB / s. You may notice increasing write speed depending on the higher variant.

Variant Sequential read speed Sequential write speed
250 GB 3400 MB / s 1500 MB / s
500 GB 3400 MB / s 2300 MB / s
1 TB 3400 MB / s 2500 MB / s
2 TB 3500 MB / s 2500 MB / s

Theoretical read / write speeds of 970 EVO | Source: SAMSUNG

Read/Write Speed of SAMSUNG 970 EVO Plus NVMe SSD

The read speed is stable for all variants of Samsung 970 EVO Plus up to 3500 MB / s. Conversely, the write speed increases as the capacity increases.

Variant Sequential read speed Sequential write speed
250 GB 3400 MB / s 2300 MB / s
500 GB 3400 MB / s 3200 MB / s
1 TB 3400 MB / s 3300 MB / s
2 TB 3500 MB / s 3300 MB / s

Theoretical read / write speeds of 970 EVO Plus | Source: SAMSUNG

Comparing the read / write speeds of both of these products, you can clearly see that the Samsung 970 EVO Plus is faster. While there isn’t that much of a difference in “read speed” considering the write speeds of each variant, the Samsung 970 EVO Plus dominates the old Samsung EVO 970.

Note: The specified read / write may differ (increase / decrease) depending on the operating system and system processor.

The abovementioned tera-bytes are written common to both of these SSDs. Moreover, TBW indicates a better service life. Samsung NVMe SSDs are reliable and durable products. So there are no issues with any of these SSDs.

Testing the SSD 970 EVO Plus: A Clear Boost?

I was not disappointed. As mentioned earlier, PC Labs received a 500GB version of the 970 EVO Plus SSD for testing, as shown below. For SSDs, performance can vary slightly depending on the capacity you’re looking at in terms of drives, with the increase being due to parallelism with more memory modules. For an insight into the 1TB version of the 970 EVO Plus SSD (as well as digging a little bit into the controller and subtleties of that drive’s caching) check out this 1TB review on Hot Hardware.

In our Crystal DiskMark 6.0 sequential read and write test, the 970 EVO Plus SSD actually showed much better write performance: 3,071 MB / s compared to 2,481 MB / s for the 970 EVO SSD. The sequential speeds of the 970 EVO Plus SSD are very similar to that of the WD Black SN750, which was just announced last week as an iterative improvement over the original WD Black NVMe SSD ($ 199.98 at Amazon UK) .

The 970 EVO Plus SSD didn’t stand out in our random read and write performance test, however. Random performance is more of a guideline than sequential disk performance for everyday computer use cases such as web browsing, application switching, and startup. It is also more difficult to measure on theoretical tests. Our test simulates random performance with a single thread and a queue depth of one thread, resulting in the 970 EVO Plus SSD reaching comparable speeds to the WD Black SN750 but slower than the 970 Pro SSD and 970 EVO SSD.

Since the random read and write tests can vary greatly depending on the number of queues and threads used, we also use a second proxy for random data access: how well a disk can copy different types of files from one location to another on the disk, using the AS- test tool SSD.

The 970 EVO Plus SSD excelled in the first of its series of tests, achieving class-leading transfer times for a single large ISO disc image file. Its times of moving a typical game folder and program folder have been very competitive as well.

Ultimately, however, the performance improvement on the SSD 970 EVO Plus won’t drastically impact your daily work, compared to the rest of the NVMe suite. As proof, just look at the fact that all Samsung and WD Black SN750 drives scored several points after the 5100 in the PCMark 8 comprehensive mass storage test, which runs productivity and gaming simulations for about an hour and judges how well the drive is handling them. Even the surprisingly expensive Intel Optane SSD 905P ($ 199.98 at Amazon UK) performed more or less the same in this test.

A Key Differentiator: Cost Per Gigabyte

So we go back to the shades of differences that distinguish the best PCIe SSDs at the moment. The reason for choosing the SSD 970 EVO Plus over the SSD 970 EVO or some other competing drive therefore boils down mainly to the price. And Samsung has managed to make some improvements on that front.

The 970 EVO Plus SSD is just $ 129 for the 500GB drive we’ve tested, which is slightly cheaper than the 970 EVO SSD and hits almost 25 cents per gigabyte. That’s an aggressive price to pay for such a competent SSD – just a year ago, you’d expect to spend at least 35 cents per gigabyte for such performance. An EVO without Plus may see price corrections when the EVO Plus hits the market, but 25 cents is a good gigabyte target to aim for in this zone.

The price of a 1TB 970 EVO Plus SSD is 25 cents per gigabyte, although 250 GB costs 36 cents per gigabyte. (As mentioned above, the price of 2 TB has yet to be announced.) The data is almost identical to that of the WD Black SN750 SSD with the same capacities.

Either it would be the perfect drive for building a gaming PC or as an upgrade to your existing desktop or laptop computer. But the slight performance advantage of the 970 EVO Plus SSD means that if absolute performance for your dollar is what matters most, this is the drive you’ll eventually want to plug into the M.2 slot.

This SSD comes in 4 capacities, 250GB, 500GB, 1TB, and 2TB, which cost $ 90, $ 130, $ 250, and $ 450, respectively. That works out to 25 cents per GB for 1 TB, and a bit more for the other two smaller sizes.


It should come as no surprise that the newer SSD model performs better than the older one. This is especially true for writing to the main NAND body as well as writing multiple queues in 4K. However, normal copy times change with changes in capacity due to different cache sizes and other related factors.

Note that the performance of 3-bit NAND memory during native write operations is not so fast. Regardless, the Samsung 970 EVO Plus can reach 3.3 GB / s in write operations and up to a staggering 3.5 GB / s in sequential reads. This latest SSD also offers random read / write IOPS of up to 620,000 / 560,000.

As soon as the cache is exhausted, the performance of all TLC drives typically slows down. The 970 EVO Plus drops to around 900 MB / s, contextually this is almost twice the speed of SATA SSDs. 900MB / s is also 250MB / s faster than the previous 970 EVO once the cache is depleted.

Intelligent TurboWrite

The cache size that Samsung describes as “Intelligent TurboWrite” generally varies according to the capacity of the drive. The 250 GB version includes 13 GB of intelligent TurboWrite, while the 500 GB version has 22 GB of intelligent TurboWrite, and 1 TB weighs 42 GB of intelligent TurboWrite. However, these numbers will be affected by the amount of data written and the degree to which the disk is full.

970 EVO Plus

In any case, rarely will users write outside of these cache amounts, and if they do, the 900Mbps transfer speed is pretty fair. But if you want to avoid a drop in performance, go for WD Black NVMe or 970 Pro which are much more expensive. If you need an inexpensive, fast, and reliable SSD, the 970 EVO Plus is the logical choice.

The read speed for 250GB / 500GB / 1TB is the same as 3,400MB / s, while the 2TB variant includes a better read speed of 3,500MB / s. You may notice increasing write speed depending on the higher variant.


DiskBench is a great tool that allows you to perform some actual tests on your disks. We wanted to test disk performance while creating data to disk as this is the most common scenario. We used a 1000 MB block out of a total of 30 blocks. The average transfer speed turned out to be only 589 MB / s, which is not all that impressive, but not too bad either.

ATTO Benchmark

The ATTO benchmark is one of the most detailed benchmarks you can find on the Internet about drives. It offers tons of tests with different settings and gives you an excellent overview of your drive’s performance. In the pictures below, we have shown both MB / s speeds and IO operations per second. We used a 32 GB file while the operations varied from 512 B to 64 MB.

Comparing the read / write speeds of both of these products, you can clearly see that the Samsung 970 EVO Plus is faster. While there isn’t that much of a difference in “read speed” considering the write speeds of each variant, the Samsung 970 EVO Plus dominates the old Samsung EVO 970.

Transitioning to 92-Layer (9xL) NAND

Last fall, Samsung unveiled its plans to move from 64L to 9xL NAND. Most Samsung SSDs that use TLC NAND will be upgraded to 9xL NAND while keeping the same SSD controllers as current products. While consumer products will remain PCIe 3.0 for now, Samsung’s top enterprise drives will receive an update to support PCIe 4.0. This means that the Samsung Phoenix controller, which is at the heart of their NVMe product line in retail, OEM and low-end data centers, will be available for another year, including the new 970 EVO Plus and related products such as the PM981a and PM983a.

Samsung’s fifth generation 9-layer NAND 3D memory was first announced at Flash Memory Summit in 2017, and mass production began in July 2018 with 256 Gb TLC matrices. Last year, however, NAND flash prices collapsed as the good yields and large production volumes of the 64L 3D NAND caused an oversupply. Major manufacturers took steps to slow down the transition to 9xL NAND to avoid worsening the situation for their profit margins, but did not stop the process completely. There is still a strong incentive to deliver annual retail product updates, so it’s no surprise that the 970 EVO Plus is now arriving.

The Samsung 9xL 3D NAND process doesn’t provide a huge increase in density to cut costs even further, but it does provide numerous performance and energy efficiency improvements that make it a good way for Samsung to upgrade a high-end product like the 970 EVO. The new generation of 3D NAND upgrades the interface between the controller and NAND to DDR 4.0 switching mode, increasing the interface speed from 800 Mb / s to 1400 Mb / s while reducing the voltage from 1.8 V to 1.2 V. This gives Samsung an advantage over the next one generation, because the 96L NAND from Intel, Micron and SK Hynix only supports the interface up to 1200Mbps, and the Toshiba / SanDisk 96L NAND is only 800Mbps.

In each NAND flash memory, Samsung has made improvements to read and programming delays which now decrease to around 50 µs and 500 µs respectively, improving by about 30%. Samsung is the only NAND manufacturer that continues to increase the number of layers without resorting to production using string stacking, which was achieved by making each layer 20% thinner, but this did not affect the write endurance rating of the drives. Samsung has clearly dropped in terms of total layers, with this generation only using 92 active layers compared to the expected 96 layers achieved by all competitors.

Specifications of the Samsung 970 EVO Plus
Capacity 250 GB 500 GB 1 TB 2 TB
Shape factor M.2 2280 one-sided
Controller Samsung Phoenix
NAND Flash Samsung 92-layer 3D TLC technology
SLC cache Min 4 GB 4 GB 6 GB TBD
Max 13 GB 22 GB 42 GB TBD
Sequential read 3500 MB / s TBD
Sequential Write (SLC) 2300 MB / s 3200 MB / s 3300 MB / s TBD
Sequential Write (TLC) 400 MB / s 900 MB / s 1700 MB / s 1750 MB / s
Random 4 KB read QD1 17 thousand IOPS 19,000 IOPS TBD
QD128 250,000 IOPS 480,000 IOPS 600,000 IOPS 620,000 IOPS
4 KB random write QD1 60,000 IOPS TBD
QD128 (SLC) 550,000 IOPS 560,000 IOPS
QD128 (TLC) 100,000 IOPS 200,000 IOPS 400,000 IOPS 420,000 IOPS
Power To read 5.0 watts 5.5 watts 5.5 watts TBD
Write 4.2 watts 5.8 watts 6.0 watts TBD
Idle 30 mW TBD
L1.2 Idle 5 mW TBD
Encryption AES 256, TCG Opal 2.0, IEEE 1667
Guarantee 5 years
Write Endurance 150 TB
0.3 DWPD
300 TB
0.3 DWPD
600 TB
0.3 DWPD
1,200 TB
0.3 DWPD
Manufacturer’s suggested retail price $ 89.99
(36 cents per GB)
$ 129.99
(26 cents per GB)
$ 249.99
(25 cents per GB)
in April

Where’s the 970 PRO Plus?

(Not to be confused with caffeine tablets – Ian)

Samsung’s 9xL plans last fall clearly missed any mention of MLC-based drives, and Samsung in particular made no mention of the 970 PRO Plus. The lack of new MLC drives for data centers or OEMs is not surprising given how exactly these markets have transitioned to TLC. On the consumer side, however, Samsung has been one of the few remaining supporters to offer MLC-based SSDs to enthusiasts and prosumers with PRO drives.

The later release date of the 2TB 970 EVO Plus suggests that the only 9xL NAND Samsung is ready for the retail market is their 256Gb TLC; 512Gb TLC and QLC parts are possibly still in the sampling phase for memory alone, or the OEM or datacenter disks are still trying and not in full production. If Samsung plans the normal MLC part on 92 layers, it is almost certainly the lowest priority to move away from the 64L, after both TLC parts and both QLC parts come out.

We cannot rule out that there will be a ‘970 PRO Plus’ this year, but it seems much more likely that by 2020 we won’t see another PRO NVMe drive with a new controller that can also support PCIe 4.0. Until then, the 970 EVO Plus takes the performance flagship for Samsung’s retail / consumer product line, and the 970 PRO is only suitable for workloads that require hundreds of GBs of continuous writing per day. For workloads that are only a few tens of GB per day or include some disk idle time for SLC cache recovery, the 970 EVO Plus can now offer both better performance and a better price than the 970 PRO.

(Samsung plans to eventually roll out the second-generation MLC version of its specialized low-latency Z-NAND version, but they are still in the process of implementing the SLC version, and the number of Z-NAND layers lags behind their overall V-NAND 3D NAND purpose. Samsung has not mentioned anything about it no plans to use Z-NAND outside of product lines in data centers. At the other end of the product spectrum, NVMe revealed plans for the 980 QVO with QLC NAND, but we’re not sure when to expect, whether it will introduce a new controller, or continue to use the controller Phoenix.)

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