Samsung SSD 840 Pro Series 256GB Solid State Drive

Like many other manufacturers, Samsung has set its sights on the growing solid-state drive (SSD) market. This past fall, the company introduced two new drives, the SSD 840 and SSD 840 Pro. Designed and built completely in-house, these two ultra-slim SSDs are powered by Samsung's own triple-core MDX controller and feature a SATA 6GB/s interface, specially-engineered wear-leveling and garbage collection algorithms and up to 512MB of cache. From here though, the similarities end. Where the SSD 840 is aimed at the cost conscious consumer, the high-performance SSD 840 Pro is equipped with Samsung's Toggle DDR2 NAND flash memory to deliver up to 540MB/s read and 520MB/s write speeds as well as a maximum of 100,000 IOPS.

For this review, we purchased the 256GB version of the SSD 840 Pro. This drive is capable of delivering up to 540MB/s sequential read and 520MB/s sequential write speeds as well as up to 100,000 random read and 90,000 random write IOPS.

The SSD 840 Pro comes in a small black box. While there aren't a lot of details on the front, the back of the box lists many of the drive's features as well as its specifications. Inside, you'll find the SSD, warranty statement, installation guide, software and manual CD and a couple of "Samsung SSD Activated" stickers for your computer's case.

Physical Features:

Like Samsung's previous SSDs, the SSD 840 Pro is very well constructed. The drive's outer casing is made entirely out of aluminum and is very strong and lightweight. The SSD 840 Pro also shares the same black and orange color scheme as the more mainstream-oriented SSD 840. In fact, the only real way to tell the two drives apart is to flip them over and look at the label on the bottom.

Like the SSD 840, the SSD 840 Pro uses Samsung's S4LN021X01-8030 controller chip. Developed entirely in house, this proprietary, triple-core MDX controller excels at multi-tasking. Based on an ARM Cortex R4 (300MHz) controller, its three CPU cores can execute multiple instructions such as reading data, writing data and optimization.

For the 256GB version of the SSD 840 Pro, Samsung used their own 32GB 21nm K9HFGY8U5A-CCK0 Toggle Mode MLC NAND flash chip. Looking at the pictures above, you can see that there are eight of these chips on the top of the PCB. The drive also has a single 512MB K4P4G324EB-FGC2 DDR2 memory chip that is used for caching.

The test system used in this review was an HP 8200 Elite. The computer came equipped with an Intel Core i5-2400 CPU, 4GB of DDR3 1333MHz memory, Seagate Barracuda 7200.12 ST3250312AS 250GB SATA 6 Gb/s hard drive, NVIDIA Quadro FX580 512MB PCIe graphics card and an Intel 82579-LM gigabit network card. For the operating system, I installed a fresh copy of Windows 7 Enterprise.

To test the performance of the Samsung SSD 840 Pro, I ran a series of benchmarks using CrystalDiskMark 3.0.1, HD Tach RW 3.0.4.0, ATTO Disk Benchmark 2.46, AS SSD, HD Tune Pro 4.61, Anvil's Storage Utilities and Iometer. For comparison, I've also included test results from the Kingston SSDNow V300, Silicon Power S70, Plextor PX-256M5P, OCZ Vertex 4, Kingston HyperX 3K, Kingston SSDNow V+200, Plextor PX-256M3P, SanDisk Extreme and Samsung 830 SSD.

As I mentioned earlier, the SSD 840 Pro is based on Samsung's latest MDX (S4LN021X01-8030) controller chip. Looking at the screenshot above, you can see that it performs equally well with both incompressible (0%) and compressible (100%) data.

CrystalDiskMark 3.0.1:

First, I ran a few quick tests using CrystalDiskMark. This benchmark tool measures the performance of a storage device by testing its sequential read and write speeds as well as its random read and write speeds using blocks 512K and 4K in size.

Samsung SSD 840 Pro 256GB

Plextor PX-256M5P

According to Samsung, the SSD 840 Pro is capable of reading at 540 MB/s and writing at 520 MB/s when connected to a SATA 6 Gb/s port. While the drive performed well, it came up a bit short of these numbers in CrystalDiskMark's sequential read and write speed tests.

Samsung SSD 840 Pro 256GB - All 0x00, 0Fill

Plextor PX-256M5P - All 0x00, 0Fill

The SSD 840 Pro performed equally well when using highly compressible 0x00 (0 Fill) data. This time around, the drive was able to read at 512.7 MB/s and write at 493.1 MB/s.

HD Tach RW 3.0.4.0:

Next, I used HD Tach to test the SSD 840 Pro's read, write and burst speeds as well as its seek times and CPU usage.

Looking at the screenshot above, you can see that the SSD 840 Pro had average read and write speeds of 431.5 MB/s and 416.3 MB/s respectively, as well as a burst speed of 341.0 MB/s.

ATTO Disk Benchmark 2.46:

I also used ATTO Disk Benchmark to test the SSD 840 Pro's sequential read and write speeds. The tests are run using blocks ranging in size from 0.5KB to 8192KB and the total length set to 256MB.

Samsung SSD 840 Pro 256GB

Plextor PX-256M5P

When tested with ATTO, the SSD 840 Pro's read speeds topped out at about 559 MB/s and its write speeds at 535 MB/s.

AS SSD:

AS SSD is a relatively new benchmark designed specifically for solid state drives. The application contains five synthetic tests used to determine the sequential and random read and write performance of a drive.

Samsung SSD 840 Pro 256GB

Plextor PX-256M5P

AS SSD also includes a copy benchmark. This test copies an ISO (two large files), program (many small files) and game (small and large files), returning the speed and duration of each.

Samsung SSD 840 Pro 256GB

Plextor PX-256M5P

HD Tune Pro 4.61:

Next, I ran a series of tests using HD Tune Pro. This hard disk utility measures a drive's performance by testing its sequential read and write speeds as well as its access time, burst rate and CPU usage. For this review, I'm also going to use it to benchmark the SSD 840 Pro's random read and write speeds, random access times and the number of operations per second.

Samsung SSD 840 Pro 256GB - HD Tune Read Benchmark

Plextor PX-256M5P - HD Tune Read Benchmark

Samsung SSD 840 Pro 256GB - HD Tune Write Benchmark

Plextor PX-256M5P - HD Tune Write Benchmark

The SSD 840 Pro performed very well when benchmarked with HD Tune. The drive had average read and write speeds of 498.9 MB/s and 426.9 MB/s, respectively, and a burst rate of 279.7 MB/s when reading

Samsung SSD 840 Pro 256GB - HD Tune Random Access Read

Plextor PX-256M5P - HD Tune Random Access Read

Samsung SSD 840 Pro 256GB - HD Tune Random Access Write

Plextor PX-256M5P - HD Tune Random Access Write

The SSD 840 Pro didn't disappoint when doing random reads and writes. When reading 4KB blocks, the drive reached 19,556 IOPS and had an average speed of 76.443 MB/s. The SSD 840 Pro was even faster when writing, reaching 22,204 IOPS with an average speed of 88.738 MB/s.

Anvil's Storage Utilities:

Anvil's Storage Utilities is another new benchmark designed with SSDs in mind. The standard storage benchmark measures a drive's performance by testing its transfer speeds, access times and IOPS.

Iometer:

Lastly, I ran a series of tests using Iometer. This tool can be configured to benchmark a number of things. In this case, I used it to measure the SSD 840 Pro's read and write speeds and the number of operations per second. The tests were run using random bytes and a queue depth of 3.

The SSD 840 Pro's performance was very similar to what we saw in our other tests. The drive was able to read at 532.81 MB/s and write at 507.10 MB/s.

The SSD 840 Pro also performed very well when doing random reads and writes. In our tests, the drive was able to write at 164.45 MB/s and read at a blazing 336.16 MB/s.

According to Samsung, the SSD 840 Pro is capable of 100,000 IOPS when reading and 90,000 IOPS when writing 4K blocks. In our tests, the drive reached 42,098 random read IOPS and 86,058 random write IOPS. Increasing the queue depth had little impact on the SSD 840 Pro's random write performance. However, with the queue depth set to 32, the drive was able to reach 97,799 random read IOPS.

TRIM Performance:

While SSDs offer many benefits, there are some downsides to using flash memory. One of the biggest issues people run into is performance degradation. Over time, an SSD will run out of fresh blocks and will have to write over data the file system has marked as deleted. This procedure is very complicated and can slow an SSD's write speeds considerably.

To fix this problem, most manufacturers have added TRIM support to their SSDs. The TRIM command allows an operating system, such as Windows 7, to tell an SSD which data blocks are no longer in use. Using this information, the drive pro-actively erases these blocks and adds them to the free block pool.

To test the SSD 840 Pro's TRIM function, I first put the drive in a "dirty" state. I used Iometer to fill the entire drive and then ran a random write test for 30 minutes. This had little impact on the SSD 840 Pro's read speed. However, its average writing speed dropped to a mere 57.9 MB/s.

Samsung SSD 840 Pro - Dirty

To see how well the SSD 840 Pro could recover,  I let the computer sit for about an hour and a half and then reran the test. Looking at the screenshot below, you can see that the drive's average writing speed jumped back up to 399.0 MB/s.

Samsung SSD 840 Pro - After Trim

Lastly, I used Samsung's SSD Magician software to perform a secure erase of the SSD 840 Pro. With the drive wiped clean, its average writing speed increased to 413.7 MB/s.

Samsung SSD 840 Pro - Secure Erase

Final Thoughts:

Samsung has another winner on its hands with the 840 Pro Series SSD. Designed and built entirely in-house, this attractive, ultra-slim SSD combines Samsung's triple-core MDX controller with their own Toggle DDR2 NAND flash memory to deliver some of the best all around performance we've seen. In our sequential read and write tests, the 256GB version of the SSD 840 Pro was able to read at speeds as high as 559 MB/s and write at speeds in excess of 500 MB/s. The drive also took the top spot in our random write tests, producing more than 86,000 IOPS at low queue depths. Best of all, it performed equally well with compressible and incompressible data and was able to sustain these speeds, even after intensive use.

The SSD 840 Pro is available now in 128GB, 256GB and 512GB capacities. Prices on Amazon.com currently range from $130 up to $500, with the 256GB version reviewed here going for about $230.

Highs:

• Available in 128GB, 256GB and 512GB capacities
• Excellent sequential read and write speeds
• Very good random read and write performance
• Performs equally well with compressible and incompressible data
• Good looking, ultra-slim design
• SATA 6Gb/s interface
• Toggle DDR MLC NAND flash
• Large SDRAM cache
• Supports TRIM, garbage collection and wear leveling
• AES 256-bit full disk encryption
• Includes SSD Magician software and Data Migration Tool
• 5 year warranty

Lows:

• Does not include an adapter bracket or cables
• Pricey