SanDisk X400 vs SAMSUNG 850 EVO: Choose Right One

In the domain of personal storage devices, SAMSUNG and SanDisk both companies are both known worldwide. So, when it comes to choosing between the best products from both these companies, you may find it hard to make a decision.

The SAMSUNG 850 EVO and SanDisk X400 are both great SSDs with almost similar theoretical performance specs. So, if someone has suggested you the SanDisk X400 and your eyes are stuck on the 850 EVO, the decision can become tough to take.

But, in this article, I am going to help you pick the right one. In fact, I will share the actual benchmark scores and then give my honest opinion about which one should you choose. So, without any further delays, let’s get started.

SAMSUNG 850 EVO vs SanDisk X400: Which one to buy?

There are several things you should keep in mind while choosing any SSD. Before picking the right one between the 850 EVO and X400, here are the things you should definitely know.

But, storage space is the first thing to discuss before anything else. SanDisk X400 has only four variants available i.e. 128GB, 256GB, 512GB, and 1TB. However, the 850 EVO also has 2TB and 4TB Variants along with these.

1. Theoretical Read/Write Speed

Let’s have a look at what both companies have to say about their product’s sequential read/write speed.

SAMSUNG 850 EVO’s Maximum Theoretical Read/Write Speed

VariantRead SpeedWrite SpeedRandom ReadRandom Write
120GB540 MB/s520 MB/s94,000 IOPS88,000 IOPS
250GB540 MB/s520 MB/s97,000 IOPS88,000 IOPS
500GB540 MB/s520 MB/s98,000 IOPS90,000 IOPS
1TB540 MB/s520 MB/s98,000 IOPS90,000 IOPS
2TB540 MB/s520 MB/s98,000 IOPS90,000 IOPS
4TB540 MB/s520 MB/s98,000 IOPS90,000 IOPS
Read/Write speed of SAMSUNG 850 EVO

SAMSUNG is promising almost similar sequential and random read/write speed with all its variants which is good. Now, let’s see what X400 has to offer.

SanDisk X400’s Maximum Theoretical Read/Write Speed

VariantRead SpeedWrite SpeedRandom ReadRandom Write
128GB540 MB/s340 MB/s93,500 IOPS60,000 IOPS
256GB540 MB/s520 MB/s93,500 IOPS60,000 IOPS
512GB540 MB/s520 MB/s93,500 IOPS75,000 IOPS
1TB545 MB/s520 MB/s95,000 IOPS75,000 IOPS
Read/Write speed of SANDISK X400

With this table, we can see that the 128GB Variant of X400 has a slower write speed i.e. 340. But, for all other variants, the speed is averaged at up to 540MB/s read and 520MB/s write.

Results: With these tables above, you can see that the X400 has very competitive sequential read/write speed but its lacking in the 4K Random read/write operations. We are going to see the impacts of this below.

2. Benchmark Scores

Enough talking about the theoretical performance specs, Let’s see how both SSDs perform when we give them real-time tasks to do. The benchmarks were done on a low-end laptop with Intel i3 10th Gen processor with 8GB of RAM.

The benchmarks were done with 100% empty SSD storage. The speed may decrease depending on the storage space occupied by the data stored in it.

SAMSUNG 850 EVO’s Benchmark Scores

VariantRead SpeedWrite Speed4K Read4K Write
120GB450 MB/s420 MB/s36.4 MB/s89.3 MB/s
250GB470 MB/s434 MB/s38.7 MB/s91.0 MB/s
500GB468 MB/s422 MB/s45.2 MB/s91.6 MB/s
1TB475 MB/s429 MB/s39.2 MB/s92.3 MB/s
2TB481 MB/s441 MB/s39.8 MB/s91.9 MB/s
4TB474 MB/s431 MB/s37.4 MB/s91MB/s
Benchmarking scores of SAMSUNG 850 EVO

With these benchmarking scores, we have observed that the 850 EVO has consistent sequential read speed averaging at around 460MB/s and write at around 430MB/s. But, the random read and write speed is pretty competitive. You get above 40MB/s 4K read and above 90MB/s 4K write speed with very rare SSDs. But, SAMSUNG is here to offer the same.

SanDisk X400’s Benchmark Scores

VariantRead SpeedWrite Speed4K Read4K Write
128GB429 MB/s250 MB/s29.5 MB/s72.2 MB/s
256GB434 MB/s310 MB/s29.1 MB/s75.6 MB/s
512GB449 MB/s358 MB/s26.8 MB/s71.9 MB/s
1TB457 MB/s390 MB/s29.7 MB/s70.4 MB/s
Benchmarking scores of SanDisk X400

With this, we can see that X400 has good sequential reading capabilities but the write speed is compromises. Also, both random read and write speeds are slower than most of its near competitors.

Results: We can say that the SAMSUNG 850 EVO is a clear winner here with great sequential and random read/write speed.

We are going to know the reasons below very soon. But, before that, let’s know more about the reliability first.

3. Endurance

It is tough to determine the TBW and the overall endurance of any SSD practically. The life of any SSD depends on the type of usage and the environment as well. But, let’s see what these both companies has to offer to you.

SAMSUNG 850 EVO Endurance

ProductEnduranceDWPD (Drive Writes Per Day)MTBF
SAMSUNG 850 EVO (120 GB)75 TBW41 GB/Day1.5 Million Hours
SAMSUNG 850 EVO (250 GB)75 TBW41 GB/Day1.5 Million Hours
SAMSUNG 850 EVO (500 GB)150 TBW82.1 GB/Day1.5 Million Hours
SAMSUNG 850 EVO (1 TB)150 TBW82.1 GB/Day1.5 Million Hours
SAMSUNG 850 EVO (2 TB)300 TBW164.3 GB/Day1.5 Million Hours
SAMSUNG 850 EVO (4 TB)300 TBW164.3 GB/Day1.5 Million Hours
Samsung 850 EVO Endurance

Know more about the TBW and SSD Endurance here.

SanDisk X400 Endurance

ProductEnduranceDWPD (Drive Writes Per Day)MTBF
SanDisk X400 (128 GB)72 TBW39.4 GB/DayUp to 1.75M hours
SanDisk X400 (256 GB)80 TBW43.8 GB/DayUp to 1.75M hours
SanDisk X400 (512 GB)160 TBW87.6 GB/DayUp to 1.75M hours
SanDisk X400 (1 TB)320 TBW173.3 GB/DayUp to 1.75M hours
SanDisk X400 SSD Endurance

Result: So, we can clearly see that the average TBW (Terabytes Written) and DWPD (Drive Writes Per Day) limits are more in the SAMSUNG SSD. So, the SAMSUNG 850 EVO also won in the Endurance test as well.

4. Price Difference

So, now when you have seen that the 850 EVO is great in terms of speed, benchmarks, and reliability, let’s see how much cheap is the X400 in comparison to it.

SAMSUNG 850 EVOPriceSanDisk X400Price
SAMSUNG 850 EVO 120 GB~$99.99SanDisk X400 128 GB$50.49
SAMSUNG 850 EVO 250 GB~$149.99SanDisk X400 256 GB$78.99
SAMSUNG 850 EVO 500 GB$269.99SanDisk X400 512 GB$122.50
SAMSUNG 850 EVO 1 TB$499.99SanDisk X400 1 TB$249.9
SAMSUNG 850 EVO 2 TB$473.89
SAMSUNG 850 EVO 4 TB$1,199.00
Price Difference table

Result: Although most of the SSDs are not available in the online markets there days, I am going to update them when they arrive back. But, it is clear that the SAMSUNG SSDs are a little bit price as compared to the SanDisk X400.

5. Cache Memory

Cache memory has a huge role in increasing SSD performance and lifetime as well. Let’s see what type of Cache memory is used by both these SSDs.

SAMSUNG 850 EVO Cache Storage:

VariantCache Storage
120 GB256 MB Low Power DDR3
250 GB, 500 GB512 MB Low Power DDR3
1 TB1 GB Low Power DDR3
2 TB2 GB Low Power DDR3
4 TB4 GB Low Power DDR3
Cache Storage used in SAMSUNG 850 EVO

Know more about the cache storage and DRAM-Less SSDs here.

Since the SSD is working on the SATA interface (i.e. up to 600 MB/s), there is no need to use very high-speed RAM. So, SAMSUNG has done a great job installing the low-power DDR3 cache storage which might be contributing to lowering the price.

SanDisk X400 Cache Storage

VariantCache Storage
128 GBSanDisk’s nCache 2.0 SLC
256 GBSanDisk’s nCache 2.0 SLC
512 GBSanDisk’s nCache 2.0 SLC
1 TBSanDisk’s nCache 2.0 SLC
Cache Storage used in SAMSUNG 850 EVO

The actual amount of cache memory is not available. But, the nCache is SanDisk’s own technology and trademark. This nCache 2.0 SLC flash is used as the cache memory for SanDisk X400’s 2nd Generation TLC NAND.

Result: We can now clearly see that the SAMSUNG is using a faster and efficient D-RAM for data cache storage. This is another reason why SAMSUNG 850 EVO is beating the X400.

5. Why SAMSUNG 850 EVO is faster than the X400?

There are a lot of reasons why SAMSUNG 850 EVO is faster and reliable than the X400. Some of those reasons are as follows.

1. Flash Storage Type

SAMSUNG is using its extraordinary V-NAND Flash which is known for its unmatched performance and endurance. However, the NAND used inside the X400 is a 2nd Generation TLC node which is efficient enough but not like the V-NAND.

So, because SAMSUNG’s SSD has the strongest roots, it can beat most of the popular SSDs out there including the X400.

2. Controller

The SanDisk X400 has the Marvell 88SS1074 SSD controller. However, the SAMSUNG 850 EVO is using two different controllers for different storage spaces.

The SAMSUNG 850 EVO (120 GB, 250 GB, and 500 GB) utilizes the Samsung MGX Controller.

The SAMSUNG 850 EVO (1 TB, 2 TB, and 4 TB) utilizes the Samsung MHX Controller. MHX is rated good for high speed and transfer functions. However, the MGX is also a good one if we look at the storage space.

3. Form Factors

The SanDisk X400 is available in two form factors i.e. 2.5”/7mm cased, M.2 (2280). The features and speed will remain the same. But, the price may vary

The SAMSUNG 850 EVO is available in three form factors 2.5 inches, mSATA, and M.2 (2280). The features and read/write speed will remain almost the same. But, the price may vary.

4. Other Important Features

ProductS.M.A.R.T.T.R.I.M.EncryptionTCG OpalDevSleep
SAMSUNG 850 EVOYesYesAES 256-bitYesYes
SanDisk X400YesYesAES 256-bitTCG Opal 2.0Yes
Special features comparison

Which one should you go for? SAMSUNG 850 EVO or SanDisk X400

SAMSUNG 850 EVO is clearly a winner in terms of speed, reliability, performance, and other various features. So, I would suggest you go for this one. It will help you make the most out of your SATA-3 interface.

However, if you use your desktop or laptop for normal tasks like media consumption or browsing, you can go with the X400 as well. Also, it is priced cheaper but has some great features to offer. If you tell me to choose between the both, I would buy SAMSUNG 850 EVO for sure.

Final Verdict

There is nothing more to be discussed about both the SSDs. I hope you will now make your decision right away without researching more.

Thanks for reading!