Samsung 840 Pro Solid State Drive Review

By Hank Tolman

Manufacturer: Samsung
Product Name: Samsung 840 Pro SSD
Model Number: MZ-7PD256BW (512GB), MZ-7PD512BW (512GB)
Price As Tested:  256GB: $204 (Amazon | Newegg), 512GB: $390 (Amazon | Newegg)

Full Disclosure: The product sample used in this article has been provided by Samsung.

For going on two years now, Samsung has been a major player in the SSD market. Before that, Samsung SSDs just didn’t compete. That has all changed with the Samsung 800 series of SSDs and even more recently with the release of Samsung’s RAPID technology for use with Samsung 840 SSDs. Samsung now competes at the top of the market and their SSDs are forces to be reckoned with. In this article, Benchmark Reviews looks at the Samsung 840 Pro SSD’s performance, with and without RAPID mode enabled.

By all rights, Samsung should be at the top of the market. Samsung is the biggest manufacturer of flash memory in the world. While it is true that most of that memory goes to other companies, Samsung is making more and more of their own consumer products. The Samsung 840 series of SSDs includes the 840, the 840 Pro, and the 840 EVO.

Not only does Samsung make their own flash, they also make their own SSD controllers and their own firmware. Those three make up all the components necessary for a Solid State Drive. Typical SSD producers may not actually manufacture any of those three components. A lot of SandForce SSDs fall into this category. Other companies might produce just their own firmware, or their own flash memory, or even their own controller. Crucial, owned by Micron, falls into the category of a manufacturer that uses their own memory. OCZ makes their own SSD controller.

Samsung makes it all; the memory, the controller, and the firmware. That gives Samsung a distinct advantage. They can make changes or adjustments to whatever part of the manufacturing process makes the most sense, rather than trying to work with what someone else has made. While the first iteration of Samsung SSDs didn’t get very high marks, that ability to improve has pushed Samsung up the ranks during recent releases. The Samsung 830 SSD received very high marks all around. I expect similar performance from the Samsung 840 Pro, and even better marks with RAPID mode enabled.

Benchmark Reviews Executive Editor, Olin Coles, provides an excellent overview in the sections below:

Solid State vs Hard Disk

Despite decades of design improvements, the hard disk drive (HDD) is still the slowest component of any personal computer system. Consider that modern desktop processors have a 1 ns response time (nanosecond = one billionth of one second), while system memory responds between 30-90 ns. Traditional hard drive technology utilizes magnetic spinning media, and even the fastest spinning mechanical storage products still exhibit a 9,000,000 ns / 9 ms initial response time (millisecond = one thousandth of one second). In more relevant terms, the processor receives the command and must then wait for system memory to fetch related data from the storage drive. This is why any computer system is only as fast as the slowest component in the data chain; usually the hard drive.

In a perfect world all of the components operate at the same speed. Until that day comes, the real-world goal for achieving optimal performance is for system memory to operate as quickly as the central processor and then for the storage drive to operate as fast as memory. With present-day technology this is an impossible task, so enthusiasts try to close the speed gaps between components as much as possible. Although system memory is up to 90x (9000%) slower than most processors, consider then that the hard drive is an added 1000x (100,000%) slower than that same memory. Essentially, these three components are as different in speed as walking is to driving and flying.

Solid State Drive technology bridges the largest gap in these response times. The difference a SSD makes to operational response times and program speeds is dramatic, and takes the storage drive from a slow ‘walking’ speed to a much faster ‘driving’ speed. Solid State Drive technology improves initial response times by more than 450x (45,000%) for applications and Operating System software, when compared to their mechanical HDD counterparts. The biggest mistake PC hardware enthusiasts make with regard to SSD technology is grading them based on bandwidth speed. File transfer speeds are important, but only so long as the operational I/O performance can sustain that bandwidth under load.

Bandwidth Speed vs Operational Performance

As we’ve explained in our SSD Benchmark Tests: SATA IDE vs AHCI Mode guide, Solid State Drive performance revolves around two dynamics: bandwidth speed (MB/s) and operational performance I/O per second (IOPS). These two metrics work together, but one is more important than the other. Consider this analogy: bandwidth determines how much cargo a ship can transport in one voyage, and operational IOPS performance is how fast the ship moves. By understanding this and applying it to SSD storage, there is a clear importance set on each variable depending on the task at hand.

For casual users, especially those with laptop or desktop computers that have been upgraded to use an SSD, the naturally quick response time is enough to automatically improve the user experience. Bandwidth speed is important, but only to the extent that operational performance meets the minimum needs of the system. If an SSD has a very high bandwidth speed but a low operational performance, it will take longer to load applications and boot the computer into Windows than if the SSD offered a higher IOPS performance.