Horace Dediu of asymco charts commodity computing up-take (as yearly sales) since 1975 in " The evolution of the computing value chain ". It includes personal computers, smartphones and more. Current PC (desktop+laptop) and Android sales are about equal at 350MM/year, with iPhones ~150MM/year and iPads closing in on 100MM/year: or near 1Bn new personal compute devices per year. With current growth rates, how soon will we saturate the IPV4 address space? There are two questions in there: How many IPV4 addresses are left? Where? Each region has its own challenges. How fast is the demand for Internet addresses growing? New Sales are not the whole story: replacements account for most sales in mature markets. The active PC fleet is now somewhat static. When the smartphone and tablet markets mature, Sales will still hold up with replacements catering for the 2-5 year product life. The 32-bit IPV4 address space can assign no more than 4Bn unique identities. My guesstimate of realis...
Researching the history of Disk Storage and RAID since Patterson et al's 1988 paper has given me some surprises. Strictly personal viewpoint, YMMV. Aerodynamic drag of (disk) platters is ∝ ω³ r⁵ (RPM^3 * radius^5) If you double the RPM of a drive, spindle drive power consumption is cubed. All that power is put into moving the air, which in a closed system, heats it. Ergo, 15K drives run hot! If you halve the size of a platter, spindle drive power consumption is reduced by the fifth-power. This is why 2½ inch drives use under 5W (and can be powered by USB bus). There's a 2003 paper by Gurumurthi on using this effect to dynamically vary drive RPM and save power. Same author in 2008 suggests disks benefit from 2 or 4 sets of heads/actuators. Either to increase streaming rate or seek time, or reduce RPM and maintain seek times. The Dynamic RPM paper to be the genesis of the current lines of "Green" drives. Western Digital quote RPM as "intellidrive", but class ...
A response to the "Public Sphere" run by Senator Lundy on "High Bandwidth for Australia". Previous comments on the National Broadband Network - about excess costs, poor design and addressing lost strategic opportunities. Future posts will be linked from here. Roger Clarke finished his presentation with a comment something like "the upside is obvious, the downside needs to talked about". Without bringing down the tone, optimism and vision of the event, enumerating the Barriers and Challenges associated with roll-out and adoption of 'universal' High Speed Broadband (HSB) in Australia allows for generating better designs/options, avoiding 'surprises' and anticipating routes around and out-of "bear pits", "Forewarned is forearmed". Who knows, new insights may emerge from this viewpoint. Alan Kay in his 2003 Turning Award speech identified the central importance of ICT: "our field is a field that's the next great...
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