Server Partition Manager

Samsung 850 Pro and Evo 2TB SSD

Samsung HDD released the world’s thinnest 4TB portable drive, namely Samsung M3 4TB Portable Drive and Samsung P3 4TB Portable Drive. After a while, it  announced the availability of two 2TB solid state drives (not mechanical hard disks): Samsung 850 Pro and Samsung Evo. It cannot be denied that Samsung is now the leader in advanced memory technology all over the world and also the most productive hard drive manufacturer.

From the above specs we know both the Pro and Evo are 2.5 inch solid state drives and employ SATA3 interface whose transfer rate reaches to 6Gbps. Well, how fast is 6Gbps? It is about 750MB/s, but in fact this is just a theoretical value, and the actual speed would be slower due to different kinds of restrictions. In addition, they employ the same controller as well as offer the same cache. Of course, there are many different specifications apart from similarities, including sequential read/write speed, random read/write speed, endurance, price, and warranty. Next, let’s analyze some of these specifications in detail.

3D V-NAND Technology, Controller, and Cache in Samsung 850 Pro and Evo 2TB SSD

After taking apart the SSD, we can see eight chips which are required to reach the 2TB capacity (4 chips each side of the PCB). That is to say capacity of every chip reaches to 256GB.

Why each chip is so large in capacity? It is owed to the use of 3-dimensional vertical flash memory technology, namely 3D V-NAND. Compared with traditional 2D planar setup which puts all memory cells horizontally, 3D V-NAND technology stacks cells vertically up to 32 layers, which makes it possible to add more memory cells in the same number of wafer bits, thus increasing capacity and lowering costs. However, the 3D V-NAND technology used by 850 Pro is a little different from that used on the 850 Evo. To be specific, 850 Pro makes use of Samsung 3D V-NAND MLC while the Evo employs Samsung 3D V-NAND TLC.

MLC is short for Multi-Level Cell while the full name of TLC is Triple Level Cell. The former enjoys up to 10,000 program/erase cycles per cell while the latter just provides about 5,000 cycles. Compared with MLC, TLC has slower read and write speeds and lower endurance limit or shorter lifespan. All these explain why Samsung 850 Pro 2TB SSD is more expensive than 850 Evo 2TB SSD. Now that the former is more expensive, naturally Samsung gives much longer warranty to it.

In addition to the 3D V-NAND technology, there are 2 big changes in Samsung 850 Pro and Evo 2TB SSD: one is the new controller, and the other is the high-speed DRAM.

The controller used on Samsung 850 Pro and Evo 2TB SSD is different from those employed on other models of Samsung 850 SSDs. Here we take the 850 Pro for example. The 128GB, 256GB, 512GB, and 1TB 850 SSDs use Samsung MEX controller, while the 2TB SSD makes use of the new MHX controller. The former controller  has a triple-core Cortex R4 processor, which is just like the SSD 840 Pro’s MDX except that the frequency of its three cores has been increased from 300MHz to 400MHz. But for the new controller MHX, so far Samsung hasn’t given any more detailed information, and we just know it is based on ARM architecture and also has 3 cores. Well then, why Samsung gives up MEX but employs MHX on 2TB SSD drives? Samsung says it is introduced because the original MEX controller isn’t designed for capacities above 1TB.

Aart from controller, Samsung 850 Pro and Evo 2TB SSD drives have made great improvement on cache support. Nowadays, NAND mapping table designs tend to require about 1MB of DRAM per 1GB of NAND for optimal performance, so a 2TB SSD requires DRAM controller capable of supporting 2GB of DRAM. Therefore, Samsung employs the 2 GB LPDDR3 for their 2TB solid state drive, which

can quicken data access speed and boost SSD service time to a large extent.

After getting to know these improvements, let’s see how fast these 2 SSD drives are.

Read/write Speed Test on Samsung 850 Pro and Evo 2TB SSD

Firstly, we tested Samsung 850 Pro 2TB SSD on AS SSD Benchmark, which is a standard testing program specially designed for solid state drive. And our testing results are shown in 2 forms: one is in MB/s, and the other is in IOPS.

MB/s Value

IOPS Value

From the test we know sequential read and write speeds of the 850 Pro are 520.68MB/s and 499.38MB/s respectively, which are slower than boasted (in the Specification part, we have said sequential read and write speeds of Samsung 850 Pro 2TB SSD are 550MB/s and 520MB/s). And the IOPS read/write speeds are also reduced. Generally, the speed reduction could be affected by hardware restrictions, quality of testing programs, or other factors. However, though there is much reduction, these values are much higher than those of similar products. For example, its 4K-64 Thrd read speed reaches to 95997IOPS, and the write speed is 79197IOPS, which are rarely seen.

Then, we tested the 850 Evo 2TB SSD also on the AS SSD Benchmark, getting the following results:

MB/s Value

IOPS Value

Sequential read and write speeds of the 850 Evo 2TB SSD are 516.68MB/s and 497.36MB/s, which are just several MB slower than those of the 850 Pro. And there are also slight reduction in other speeds, like 4k speed and 4k-64Trd speed. To some extent, the 850 Evo 2TB SSD can be matched with the 850 Pro SSD in read-write speed.

Next, we tested both the Pro and Evo on CrystalDiskMark, which is an easy to use but professional disk testing app and provides users with all-sided testing items, including consequential read/write speed, 512K read/write performance, 4K data packet read/write speed, and random performance under 32 Queue Depth.

Speed test on 850 Pro

Speed Test on 850 Evo

From the tests on CrystalDiskMark we know sequential read/write speeds of the 850 Pro reach to 549MB/s and 528.4MB/s, and 4K read speed is 46.83MB/s while write speed is 171.2MB/s. And the speeds of the 850 Evo are slightly slower than those of the 850 Pro. Though these are not ultimate speeds but quite rare in SATA3 products.

To summary, since Samsung 850 Evo 2TB SSD has nearly the same read-write speed (just several MB slower) as Samsung 850 Pro 2TB SSD, for me, I’d like to buy the Evo. After all, the Evo is $200 cheaper than the Pro. However, if you consider endurance and warranty, 850 Pro would be a good choice.

However, SSD read-write performance can be affected by lots of factors, among which 4K misalignment is the most serious one. If partitions on SSD are misaligned, read-write performance will be heavily reduced. And we even can say SSD with unaligned partitions functions just like a mechanical hard disk. For more details, please see Partition Align. Therefore, to align SSD partitions regularly is a necessity for all SSD users.

In Windows Vista and latter released Windows OS, newly created partitions will be aligned automatically, but after doing operations like resize partition and move partition location, the originally aligned partition may be unaligned. In addition, if users clone partitions to SSD, these cloned partitions are always misaligned. Under these situations, users had better employ a third party partitioning tool to align partitions since Windows built-in programs cannot do it without data loss (users have to recreate partition), and next we recommend a freeware.

MiniTool Partitioning Solutions to Samsung 850 Pro and Evo 2TB SSD

Among all MiniTool products, MiniTool Partition Wizard is highly recommended for Samsung SSD users. It is a piece of free partitioning software for Windows home users, with all-sided functions to satisfy SSD users.

“Align All Partitions”: detect the entire hard disk to find all misaligned partitions, and then align detected partitions in one step.
“Copy Disk”: clone the entire HDD to SSD or copy the whole SSD to HDD for data migration or backup.
“Migrate OS to SSD/HD Wizard”: this is a quite useful function if you want to transfer Windows from HDD to SSD without reinstallation, and all files will be under great protection. Of course, Samsung provides users with a Data Migration tool to transfer data to solid state drive, but this program is not as excellent as we expect. On some famous forums like Tom’s Hardware and Windows Seven Forums we find lots of users failed to do system migration via this program and some of them even suffered from system crash. Now that MiniTool Partition Wizard is free and powerful, why not choose it!

“Align Partition”: help align a single partition without bringing any damage to data.
“Copy Partition”: copy certain partition from HDD to SSD or from SSD to HDD without affecting data.
“Extend Partition”: enlarge both data partition and system partition by taking free space from other partitions on the same solid state drive.
“Set Partition as Logical”: set one of primary partitions as logical, and then you can create more than 4 partitions.

Of course, there are many other partitioning functions provided in MiniTool Partition Wizard, such as convert file system, change cluster size, and split partition. If you want to better use Samsung 850 Pro or Evo 2TB SSD, try downloading this freeware to do corresponding management. In addition, apart from partitioning operations, MiniTool provides Samsung SSD users with data security solutions. To be specific, MiniTool Power Data Recovery, a professional data recovery software on Windows platform, can help complete wonderful data recovery tasks if you lose some important data unluckily.

There are 4 data recovery modules in total, and you can choose This PC for Samsung SSD users.

• This PC: this data recovery module focuses on recovering lost or deleted data from damaged, RAW or formatted partitions.
• Removable Disk Drive: it is designed to recover lost photos, mp3/mp4 files, and videos from flash drives and memory sticks.
• Hard Disk Drive: it can recover files after partition loss or deletion.
• CD/DVD Drive: it helps to recover data from formatted or erased CD/DVD discs.

However, when making data recovery on solid state drive, users should pay attention to the feature TRIM of SSD. If this feature is enabled when we are deleting files, data recovery may be impossible. For more details, please see SSD Data Recovery.