Post on 13-Mar-2020
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The Evolution of Solid State DrivesCH R IST IA N WELCHCPT R 3 80MA R CH 1 2 , 201 8
History• First invented in 1950s
• Initially relied on two technologies• Charged Capacitor Read Only Storage (CCROS)
• Magnetic core memory
• StorageTek marketed a “RAM-based” drive geared for the IBM mainframe market in 1978
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StorageTek STC-4305 – the precursor to modern RAM-based drives
“Recent” History• From ~1980 until ~2000, RAM-
based SSDs dominated the market
• In 2004, BitMicro demonstrated the efficacy of flash-based memory
• Widespread use of flash nearly annihilated RAM-based SSDs
Source: https://www.macworld.com/article/2009983/hard-disk-drives-vs-solidstate-drives-are-ssds-finally-worth-the-money.html
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Architecture Comparison
F LA SH -B A SED
• Fast!
• Persistent data
• Limited read/write endurance
• Expensive
• Rugged
R A M-B A SED
• Really fast!
• No data persistence
• “Unlimited” read/write endurance
• Really expensive!
• Not rugged
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Architecture Comparison
Table of Storage Technologies and Key Metrics - source Violin Memory
Technologies Capacity (GB) Latency (µS) IOPs Cost / IOPs ($) Cost / GB ($)
Capacity HDDs 2,500 12,000 600 13.3 3
Performance HDDs 700 7000 1,200 16.6 28
Flash SSDs 700 200 500 140 100
Flash SSDs (read only) 700 45 50,000 1.4 100
DRAM SSDs 250 3 200,000 0.5 400Notes:1 - Metrics are all normalized as typical rackmount system statistics per U of height (1.75")2 - Latency and IOPs estimates assume same numbers of random reads and writes3 - Latency and IOPs estimates assume 4K block sizes
Source: http://www.storagesearch.com/ssd-ram-v-flash.html
Future• Magnetic disks are here to stay, for now• Massive
• Reliable
• Flash/DRAM hybrid drives
• Candidate technologies• PRAM (Phase-change RAM)
• FRAM (Ferroelectric RAM)
• RRAM (Resistive-RAM)
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References• http://meseec.ce.rit.edu/551-projects/fall2010/1-4.pdf
• http://www.storagereview.com/origin_solid_state_drives
• http://www.spkaa.com/blog/to-ssd-or-not-to-ssd/
• http://www.eeherald.com/section/design-guide/FRAM-MRAM-PRAM-nonvolatile-flash-replacement-memories.html
• https://www.ece.umd.edu/~blj/CS-590.26/micron-tn2919.pdf
• https://compas.cs.stonybrook.edu/~nhonarmand/courses/sp15/cse502/slides/06-main_mem.pdf
• https://www.pcworld.com/article/246617/storage/evolution-of-the-solid-state-drive.html
• http://ieeexplore.ieee.org/abstract/document/5257331/?reload=true
• https://queue.acm.org/detail.cfm?id=2385276
• http://www.eeherald.com/section/design-guide/FRAM-MRAM-PRAM-nonvolatile-flash-replacement-memories.html
• http://www.storagesearch.com/ssd-ram-v-flash.html
• http://www.computerhistory.org/revolution/mainframe-computers/7/164/578