Flashes of success: The SSD wave

BANGALORE, INDIA: What will the impact of the flash solid state disk (SSD) drives, be in the hard disk drive market?

This is a common question being asked by many people today. To answer this question, we must first know how the SSD and hard disk drive (HDD) technology has grown in the last decade.

Also Read: Hard or flash: Who to drive the storage market?

However, before we come to the growth of the SSD and HDD technology, we must understand what an SSD is.

A flash SSD is electrically, mechanically, software and interface-wise compatible to  a conventional hard disk drive with the storage media being a non-volatile memory such as Nand Flash, instead of a magnetic platter.

Hard disk capacity has grown more than 17 times during 2000 to 2010. 3.5 inches HDD capacity has also increased from 200GB to 3.5TB. Today, to 4TB is on the verge of being announced.

In February 2000, 15K revolutions per minute (RPM) drives were announced by Seagate. Since then there has been no improvement in the RPM and rotational latency. There is also uncertainty on whether 20K RPM disks will be mechanically feasible.

During the same period, the Single Level Cell (SLC) /Multi Level Cell (MLC) flash SSD capacity also expanded by around 100 times. This meant that 3.5 inches SSD capacity, which was around 20GB in 2001, increased to 2TB in March 2011.

Flash SSD random IOPS also increased by more than 120 times during the same period. However, HDD drives random IOPS did not register significant changes despite the prevalence of different technologies and interfaces, such as Integrated Drive Interface, Small Computer System Interface, Serial Attached Storage, Serial Advanced Technology Attachment , Fiber Channel.

Today, 50 per cent of the HDD market is held by HDD manufacturer Western Digital, after its acquisition of Hitachi GST. The remaining 40 per cent is held by Seagate, after its acquisition of Samsung hard disk storage arm, followed by Toshiba which holds the remaining 10 per cent.

Both Seagate and WD offer flash SSD HD as a part of its product portfolio. However, the revenue from flash SSDs continues to constitute a very small percentage of the HDD revenue pie.

{#PageBreak#}

The advantages of flash SSD drives are many:

While it emulates a normal hard disk drive, it is capable of high performance (above 1million IOPs).

Flash SSD drives also do not have any moving part and are durable, which allows it to withstand hostile environment and vibration.

It consumes less power.

For servers, SSDs can speed up the server applications by five to 40 times. Even with a server having 1/4th the number of cores, the server application can run ten times faster.

Server OEMs promising to demonstrate enhanced performance to “performance crazy” customers of their multi-core processors will incorporate flash SSDs as a part of the direct attached storage solution.

Use of SSDs can speed up laptop and iPad /iPhones and handheld devices while making them lighter and increasing battery life.

The major disadvantage is the cost. A 620GB flash SSD may cost around Rs. 2 lakh whereas 600GB SAS disk will only cost around Rs. 15,000 only. Another disadvantage is the choice of the Flash SSD. For the same capacity, the price may vary 1:10.

Less expensive SSDs typically have write speeds significantly lower than their read speeds. Whereas, higher performing SSDs may have a better and balanced read and write speed.

As per Seagate and WD, the present global production capacity of flash SSDs is not even 10 per cent of the total enterprise market. There is bullishness amongst the manufacturers that the HDD sales will continue to grow in the enterprise market.

Having said that, an enormous investment will be required to increase SSD production to match the present day HDD demands. Moreover, the cost of SSD has to really become competitive to replace HDDs.

Some OEMs may use a hybrid option, combining SSD and HDD to enhance performance. 

Since high cost remains a key concern for SSD adoption, our personal view on the usage of SSD is as follows:

In the next four to five years, the HDD industry would grow at a healthy pace, however will subsequently see a dip in growth. In the next ten years, we envisage the same manufacturers moving to alternate storage and memory technologies.

In the next three to four years, flash SSD industry will also grow and the price of MLC Flash will fall substantially resulting in greater adoption of SSD.

Flash SSD will be a leading choice in applications where storage size will be limited but applications would need to run faster e.g.  iPad , Tablet PCs , Notebooks etc.

Desktop and entertainment PC, used for music and video applications will continue to use HDD until the flash costs become affordable and comparable to HDD pricing.

HDD will survive in applications where the storage requirement is an order above the standard available flash SSD.

In other applications, where storage capacity requirement is much higher, HDD will prevail.

In high performance applications, where disk space is substantially huge, hybrid solutions may be adopted, where the flash SSD will run the application and HDD will have the backend storage and databases.

The author is chief technology officer, PwC India.

(The opinions expressed here in are the author's and do not represent CIOL's)