SSD: The last days of HDD?

Lately specialists are discussing that the last days of hard disks (HDD) are on the horizon and that they will be replaced by solid-state drives (SSD). Some companies, including Samsung, don’t think that way. They expect HDD to keep its position in the market for at least a few more years thanks to good capacity at a good price. The end of their days is however unpreventable - not only because of the old technology and high energy use, but also their larger size.

In my opinion, SSDs are great. Providing a higher speed of data transfer, lower energy consumption and lower noise - altogether this makes them the perfect choice. The bad news, their price: ten times more expensive than HDDs with the same capacity. So, what should we pick – SSD, the faster and more expensive one, or the HDD with big capacity and lower price.

Most of the computer owners today choose HDD. Samsung considers that the SSD market is still in an early stage, and they are mainly used in notebooks for their physical size. In the traditional market for personal computers it’s typical the user chose his own configuration, but lots of pre-configured systems with a SSD disk inside appear.

This means that the change is inevitable. One technology becomes popular; users start to prefer it over another; and each company has its own way to attract those users. Intel for example presented their 80 GB SSD for $595. This price is still quite high for the common user. I personally wouldn't buy a SSD yet.

According to Samsung, to lower SSD prices, cells with many levels should be used (MLC) so that each cell can contain more than one bit of information. Until now only single level cells (SLC) types of SSD were used. The difference between SLC and MLC consist in the bits that rests within one cell of the disk – while there is only one bit per cell in the SLCs, there are two (MBC) or more in MLCs.

Although MLCs are cheaper, in terms of performance SLCs are better. Let's pretend they are cars, the Multi-Level Cell disk will be a van and the Single Level Cell disk a be a Porsche. Now, let's look at the pros and cons – the van has a lot of cargo space and is a lot cheaper, but slower. On the other hand the Porsche is dozens of time more expensive but is also a lot faster and better in terms of performance.

Developing and using MLC technology will provide us with lower final prices on the SSD disks. However, you won't find the slower transfer speed and the higher energy use in the marketing specs. Also the van (MLC) is not as strong and outlasting as the Porsche (SLC). If a failure at cell level occurs, you will lose 2 or more bits (MLC) of information versus 1 bit of information (SLC).

Memory experts OCZ have already released a new MLC type of solid state disk. The usage of the Multi Level Cell technology has lowered the price by roughly 35%. They believe MLC disks will completely replace SLC ones. Further proof is that even Samsung is changing their main manufacturing line from a single cell to a multilevel cell level one.

There is also an interesting trend about combining both methods into a single drive. One part will be multi cellular while the other will be single. While keeping most of the data into the MLC part of the disk, the SLC one will be used for frequently accessed information. This way we benefit from both technologies and a lower final price.

The SSD technology is developing fast, doubling their technological possibilities each year, while the HDDs stay behind with only 50% improvement. The days where the normal user will prefer SSD over HDD are around the corner.

It’s clear that HDD won’t disappear from tomorrow and maybe they can even outlive flash memory. Recently IBM stated that the company won't completely give up on HDD until 2018. No matter that computers are evolving so fast; archival storage in large enterprises often still uses tapes. HDDs will still be around in enterprise storage for a long time, but they won't be on your desk for too much longer.