Finding Middle Ground A comparison of solid state andhybrid hard drives: Are hybrids really the best of both worlds? By: Addison Roy and Brendan Banbury
What makes aSSD tick?• An SSD (solid-state drive) is a storage device that stores persistent data on solid-state flash memory.• They are very different from Hybrid and traditional hard drives because they have no moving parts at all.• An SSD has an array of semiconductor memory organized as a disk drive, using integrated circuits instead of magnetic or optical media.• Most SSDs use NAND based flash technology which will retain data without power.• SSD manufacturers use non- volatile NAND flash memory because of the lower cost compared to DRAM and the ability to retain the data without a constant power supply
Solid State Drives:The Beginning.• The origins of SSDs actually started in the 1950’s . Magnetic core memory and card capacitor read-only store (CCROS) were called auxiliary memory units and emerged during the era of vacuum tube computers. Unfortunately with the introduction of cheaper drum storage units their use was discontinued.• In 1976 Dataram introduced the world’s first solid-state drive. It provided a massive 2 MB of storage.• This setup, including controller board cost $9,700.00 in 1977 which would be approx. $36,317.00 today.• Then in 1995 an Israeli firm M- systems developed the template for the flash based SSDs we are familiar with today. Image Source: ddrdrive.com• Storage capacity has continued to increase while prices have decreased
Combining the Best of BothWorlds: Hybrid Drives.•In simplest terms: HDD with asupersized adaptive cache.•64MB cache VS 4-64GB SSD or RAMflash memory onboard drive.•Mostly non-volatile; RAM-based W/Obattery backup exc.•Onboard software analyzes usepatterns.•Commonly used programs and filesautomatically or manually written toSSD cache.•Files replaced and added to cache asuser’s needs change.•For standard use, performs like a SSD. Image Source: engadget.comDisk platter only spins when cache isfull or requested data is on the disk.
Newer Than you Think.•HDD and SSD came out in the 1950’s…•Someone finally decided to combinethem in 2007.•Hybrid innovators: Seagate andSamsung.•Software issues with Windows Vistakept Hybrid drives in obscurity until2010. (Seagate Momentus XT)•They are still far less common thanstandalone HDD or SSD.•Still, a market niche exists, but likelynot for long.•With SSD capacity growing and costplummeting, hybrids will either become Image Source: hardmac.comobsolete, or large SSD caches in HDDwill become standard.
The pros.• SSD Hybrid:• Speed • Much faster than a HDD when the cache – Almost instant start-up times is used effectively. Only slightly slower – Consumer product data transfer than a SSD. rate usually ranges from 100 MB/s • Primarily disk based storage. Much to 600 MB/s higher capacity. Write limit for data – Random access time is about 0.1 ms blocks not a problem for HDD portion of because data is access directly from drive. the flash memory • Very inexpensive compared to SSD: Cost• No moving parts per unit of storage closer to HDD model. – Very resistant to shock and vibration • Significantly less power consumption than HDD. Platter only spins when – Almost silent needed. – Small and light weight • SSD portion can be manually managed – Can tolerate higher temperatures with new models. New models also than HHDs allows use on an unsupported OS.
The cons.• SSD Hybrid:• SSDs can only be erased a limited number • Un-cached memory requests are slower than of times before it fails. Although the traditional HDD. Platter needs additional technology has developed to manage this time to spin up. limitation and allow the drives to last a • If management of the flash memory is poor, number of years. the advantages of a hybrid solution are lost.• Storage capacity is around 2 TBs but ones In addition to more time spent writing data to the flash drive: that size are extremely pricey – Additional power consumption comes• Price from frequent spin-ups of the platter, – SSDs cost approximately US$0.65 per potentially more than a traditional HDD. GB – A significantly reduced lifetime. Flash• 64GB – 240 GB are reasonably priced at memory is frequently re-written (SSD have limited writes compared to HDD). Most $99.00 to $250.00 wear on HDD occur in spin-up and spin-• above that prices can get extremely high down cycles. More money spent on• OCZ 460 GB for $1,099.99 replacements.• OCZ 960 GB for $2,599.00• OCZ 1.2TB for 5,$399.99
But Which one Should you Choose?• Solid-State Drive: Hybrid:• When speed is the • When speed and number one priority. capacity are both – Smaller SSDs are important for a user reasonably priced seeking: – Large storage capacity is – A money-saving build. available but can be – Miniature cases with costly limited space. – Money is no object – Small laptops with only one HDD slot.