SSD - Solid State Hard Drives

Developed as early as the 1980s, Solid State Drives (SSD) have, primarily because of cost, been largely restricted to military applications and critical enterprise activities requiring enhanced transaction performance for large databases and other similar demanding applications. This situation in now changing with cost reductions bringing SSD to a price point where they are now beginning to enter the general consumer computing and electronics market. The iPhone and iPod are in fact already based on SSD technology.

Intel SSD

The solid state semiconductor technology of an SSD is similar to the familiar Secure Digital (SD) card found in digital camera. Unlike conventional hard disk drive (HDD) with rotating platters and a moving arm, an SSD has no moving parts. An SSD also requires no power retain data which can persist for up to 10 years.

Reliability

The lack of moving components gives SSDs their greater robustness towards shock, vibration, temperature extremes and humidity. Solid state memory can survive being dropped as well as exposure to magnetic fields and water. One can understand why they are popular for military applications. Ruggedness is also part of the reason that SSD are already found in mobile consumer electronics.

Speed

Another advantage of SSD is speed of data access. Access times for SSD are typically 35 to 100 micro-seconds compared to 5,000 to 10,000 micro-seconds for a conventional HDD. It’s important to note however, that system redesign is required to achieve the full benefits of having an SSD. Recent research by IDC has indicated that the performance gap between 7,200 rpm 2.5 inch drives and systems with SSD is smaller than expected. Performance of the entire system was the main factor to the smaller than expected gap rather than just the performance of the SSD.

Less Heat – Lower Power

SSD produce less waste heat and have lower power requirements compared to conventional HDD. Reduced energy use equates to smaller power supply modules being required and cheaper electricity bills. Reduced heat load means less cooling is required which, in some cases, can eliminate the need for cooling fans.

Further improvements are on the horizon with a recently developed inductive coupling wireless communication technology promising to significantly reduce SSDs internal wiring requirements and power consumption (by some 50 percent).

SSD Lifespan

A conventional computer HDD typically has a lifespan that exceeds 3 years and can reach 5 years. Intel are claiming 5 years “useful life” for their X-18M SSD based on the assumption of a hefty data writing load of 100GB/day. SSD manufacturer Metron are willing to offer a 5 year warranty on their SSD Pro 7000 series.

Samsung’s multi-level cell (MLC) 128GB and 64GB SSD are included as an option for Dell’s Laitude, XPS, Alienware and Precision laptop models. Samsung state that these SSD will last about 20 times longer than the generally accepted life span of a notebook HDD (well in excess of notebook life).

Capacity

Two (2) TB is the current maximum capacity available in a conventional HDD (Western Digital’s 2TB WD Caviar Green). Hitachi is aiming for 4TB desktop drives using new nanometer recording technologies by 2011.

The highest capacity SSD is the 1TB Nitro by pureSilicon Inc (at far higher cost). PureSilicon have achieved a truly impressive 15.4GB per cubic centimetre. The estimated Mean Time to Failure (MTTF) is equally impressive at 2 million hours (228 years).

Cost

Cost is the primary reason SSD have not taken off yet in the consumer computing and electronic markets. At the moment, consumers pay a fairly hefty premium for a SSD with the price premium reaching $600 or more. Fortunately, this situation is changing rapidly with research firm IDC reporting that costs are decreasing at an impressive 40 to 50 percent annually. They expect that price parity may be achieved by 2011.