Thursday, December 12, 2013

UK National Archive

Joe Fay at The Register has an interesting piece about a tour of the UK National Archive.

The archive has an excellent and comprehensive approach to preserving the UK government's Web presence:
It uses a crawler to trawl the UK government’s web estate, aiming to hit sites every six months. With the government looking to shutter many obscure or unloved sites, the pressure is on. The web archive currently stands at around 80TB, with the crawler pulling in 1.6TB a month. At time of writing, there are 3 billion urls in the archive, with 1 billion captured last year alone.But does anyone really care? Seems like they do. Espley said the archive gets around 15 to 20 million page views a month. This often maps to current events - the assumption being that visitors are often cross checking current government positions/statements against previous positions.
One must hope that the cross-checking doesn't turn up anything embarrassing  enough to imperil the Archive's budget ...

Friday, December 6, 2013

Diminishing Returns

One of the reasons for the slowing of Kryder's Law has been that the investment needed to get successive generations of disk technology into the market has been increasing. Assuming per-drive costs and volumes are approximately stable, this means that a technology generation has to stay in the market longer to recoup its development costs. Thus, even if the proportional density increase in each generation is the same, because the generations are spaced further apart, the result is a slower Kryder's Law.

Henry Samueli, CTO of Broadcom, makes the same point about Moore's Law. As the feature size of successive chip generations decreases, the cost of the manufacturing technology increases. And the techniques needed, such as FinFET and other 3D technologies, also slow down and increase the cost of using the manufacturing technology:
Process nodes themselves still have room to advance, but they may also be headed for a wall in about 15 years, Samueli said. After another three generations or so, chips will probably reach 5nm, and at that point there will be only 10 atoms from the beginning to the end of each transistor gate, he said. Beyond that, further advances may be impossible.
"You can't build a transistor with one atom," Samueli said. There's no obvious path forward at that point, either. "As of yet, we have not seen a viable replacement for the CMOS transistor as we've known it for the last 50 years."
... the ongoing bargain of getting more for less eventually will end, Samueli said. "We've been spoiled by these devices getting cheaper and cheaper and cheaper in every generation. We're just going to have to live with prices leveling off," he said.
Both of these are simply applications of the Law of Diminishing Returns.

Wednesday, December 4, 2013

The Memory Hole

Peter van Buren understands the 1984 analogy that drove us to assume a very powerful adversary when we designed the LOCKSS system a decade and a half ago.