ContentsIntroductionForm factorArchitecture & FunctionSSD vs HDD – Start-Up TestTechnical Comparison of SSD & HDDAdvantagesDisadvantagesSSD ApplicationsConclusion
IntroductionIn 1995, M-Systems introduced first flash-based solid-statedrives.A solid-state drive (SSD) is a data storage device thatuses solid state memory to store persistent data and SSDs usesame I/O interfaces developed for hard disk drives.SSDs do not have any moving mechanical components, whichdistinguishes them from traditional magnetic disks such as harddisk drives (HDDs).SSDs use NAND-based flash memory or DRAM to store data.
Form FactorStandard HDD form factorsBox form factorsBare-board form factorsBall grid array form factors
Form FactorStandard HDD form factors – is equal to size of traditional HDD form factors like3.5", 2.5”2.55’’ HDD form factor
Form FactorBox form factors – mainly used by DRAM based SSDs ,as they need externalpower supply or battery pack.Box form factor
Form FactorBare-board form factors - Form factor which were more common to memorymodules(RAM)Bare-board form factor
Form FactorBall grid array form factors - small chip package size to fit into Embeded systemsBare-board form factor
MemoryFlash memory-based SSDs:use non-volatile NAND flash memoryAbility to retain the data without a constant power supplylower cost compared to DRAMFlash memory SSDs are slower than DRAM solutions.DRAM-based SSDs:Based on volatile memory such as DRAMinternal battery or an external AC/DC adapter is needed tohold the dataultrafast data accessprimarily to accelerate applicationsHigher cost compared to NAND flash memory
Controller The controller is an embedded processor and executes firmware-level code.Functions:Error correction (ECC)Wear levelingBad block mappingRead scrubbing and read disturb managementRead and write cachingGarbage collectionEncryption
Cache or Buffer:A flash-based SSD typically uses a small amount ofDRAM as a cache, similar to the cache in hard diskdrives.
Host interfaceSerial ATA (SATA)SAS - Serial attached SCSI (generally found on servers)PCI ExpressFibre Channel (almost exclusively found on servers)USBParallel ATA (IDE) interface (mostly replaced by SATA)
SSD vs HDD - Start-Up Speed Test➔This video shows the speed differeence between a solid state drive and standardhard drive on a Windows 7 PC.
Technical Comparison of SSD & HDDSolid-state drive Hard disk driveRandom access time0.1 msRandom access time5~10 msRead latency timeVery lowRead latency timehigh100MB/s to 500MB/s 50MB/s to 100MB/s.High ReliabilitySSDs have no moving parts to failmechanically.Low ReliabilityHDDs have moving parts and are subjectto sudden failure;small and light in weight. relatively large and heavyIn 2013 SSDs were available in sizes up to512GB,In 2013 HDDs of up to 4TB wereavailable.power consuption 2 watts 12 watts.As of 2013 NAND flash SSDs cost aboutRs.31000 for 500GBAs of 2013 HDDs cost about Rs.3200 for500GB drives
AdvantagesHigh performance – siginificantly faster than a standardHDDFaster seek time – upto 60x faster than HDDHigher reliablity – no moving parts,can withstand 1500Gsoperating shockLower power – Lesser power consuption ,cooler operationSilent operation – ideal for post production enviornmentsLighter weight – perfect for portable devicesWider operating Temp. - 0c – 70c
DisadvantagesThey are more expensive than traditional harddrivesThey currently offer less storage space thantraditional hard drives.Slower Write Speed on low-end Models(MLCbased types)
SSD ApplicationsServersDesktop computersLaptopsUltrabooksHD CamcordersSmart TvCCTV Digital Video Recorder (DVR)Set-Top BoxesGaming Consoles
ConclusionFaster Data AccessLess Power UsageHigher ReliabilityLatest high-end laptops and ultrabooks nowcomes with SSDIn comming years SSD Will Replace Hard DiskDrives