Transcend ESD400 Portable USB3 SSD Review
By David Ramsey
Full Disclosure: Transcend Information Inc. provided the product sample used in this article.
Transcend Information Inc. was founded in Taiwan in 1988, and the company prides itself on “organizing your digital life.” Their new ESD400 series of external USB SSDs is their entry into the market for portable, USB-powered SSDs that aims to replace the mature 2.5″ hard drive that’s dominated the small external drive market for years. With sequential read and write speeds both spec’d in the range of 400 megabytes per second, the rated performance of this drive is vastly better than any spinning hard drive. Benchmark Reviews checks out the 256GB version of the ESD400 in this review.
|Interface||USB 3.0 (5gbs)|
|Form Factor||Custom, 92mm x 62mm x 10.5mm|
|NAND||MLC NAND Flash|
|Max. Read||Up to 410 MB/sec|
|Max. Write||Up to 380 MB/sec|
Solid State vs Hard Disk
No matter how fast your processor, memory, or video card is, your computer will still be limited by its slowest component: the hard disk. While hard disk speed has improved tremendously since the “early days”, with large caches and 10,000RPM spindle speeds, even the fastest hard disk’s performance is glacial compared to the rest of the computer. The situation only gets worse with modern pre-emptive multitasking operating systems, where dozens of threads are running simultaneously and competing for your disk’s limited response time and bandwidth.
Consider: the average time to move a high-performance hard disk’s read/write head to a new track will be less than 10ms, which seems pretty fast. But your CPU is galloping along at billions of cycles per second, and will spend a significant amount of its time just waiting for the hard disk to fulfill its last request. Hard disk performance has plateaued in the last few years, running up against the physical limitations of spindle speeds, magnetic media density, and head servomotor performance. At the end of the day, disks are limited by the fact that they’re comprised of physical, moving parts.
With no moving parts, Solid State Drive technology removes this bottleneck. The difference an SSD makes to operational response times and program speeds is dramatic: while a faster video card makes your games faster, and a faster processor makes compute-bound tasks faster, Solid State Drive technology makes your entire system faster, improving 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 alone. 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 may be 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 that 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.