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This document delves into key technology trends from September 2011, emphasizing the evolution and performance of processors, SSDs, and storage technology. It discusses the advancements in multi-core processors (MIMD) and GPUs (SIMD), highlighting their performance improvements. The analysis of SSDs includes latency and durability metrics, reflecting on storage pricing trends influenced by market dynamics. Furthermore, it speculates on the future of memory and data management, predicting that memory will become integral to computing, with SSDs evolving into essential archival tools.
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CS 294-42: Technology Trends September 12, 2011 Ion Stoica (http://www.cs.berkeley.edu/~istoica/classes/cs294/11/)
“Skate where the puck's going, not where it's been” – Walter Gretzky
Processors • MIMD (Multi-Core Processors) – linear increase: two additional cores every two years • SIMD (GPUs) – exponential increase: width double every four years
SSDs • Performance: • Reads: 25us latency • Write: 200us latency • Erase: 1,5 ms • Steady state, when SSD full • One erase every 64 or 128 reads (depending on page size) • Lifetime: 100,000-1 million writes per page Rule of thumb: writes 10x more expensive than reads, and erases 10x more expensive than writes
Storage Performance & Price 1http://www.fastestssd.com/featured/ssd-rankings-the-fastest-solid-state-drives/ Bwdth: SSD up to x10 than HDD, DRAM > x10 than SSD Price: HDD x20 less than SSD, SSD x5 less than DRAM
Storage Price Trends • RAMs: x2 every ~20 month (http://www.jcmit.com/memoryprice.htm) • 1990-2000: x75 decrease • 2000-2010: x63 decrease • Disks: x2 decrease every ~2 years • SSDs prices dropped faster than disk prices for last 5 year(http://rogerluethy.wordpress.com/2010/12/07/price-trends-of-hdds-vs-ssds/) • But decrease slightly less over last year Storage price halves every ~2 years
Hard Drives (25 years ago) • IBM Personal Computer/AT (1986) • 30 MB hard disk - $500 • 30-40ms seek time • 0.7-1 MB/s (est.) 30-40sec to scan entire disk
Memory (today) • 96 GB RAM - $650-800 (ECC RAM) • Memory bus speed: 10-16 GB/s 6-10sec to scan entire memory!
Working Set (Today) • When was the last time your experience trashing on your laptop? • Memory growing faster than application’s needs – conjecture Today’s memory, yesterday’s disk!
Working Set – Datacenters (Ganesh Ananthanarayanan) • % of jobs whose full inputs fit in memory (~1 week) Nearly all jobs’ inputs fitting in main memory in near future?
(Random) Thoughts • Today’s disks, yesterday’s tapes [John Ousterhout] • Today’s memory, yesterday’s disk? Or should be today’s SSDs, yesterday’s disks? • SSDs not great for caches (due limited writes) • Perfect for archival though and GFS-like filer systems ;-) • In-memory computation not enough for interactive workloads • Parallelism only way out if need to touch a lot of data
(Random) Thoughts (cont’d) • Today’s servers in Hadoop clusters: 10-12 disks • Up to 1GB/s bwdth • How to take advantage of this? • GPU use will only increase: faster increase in processing power than CPUs • Need better support for virtualization • What to do about memory bwdth? • For data intensive apps, locality will continue to be critical
Predictions?? • Memory the new disk • Working sets of more and more apps will fit in memory • SSDs will become the new tape (archival) • GPUs: main driver for increasing processing power • Will be integrated in the main processor
