From: Ben Goertzel (ben@goertzel.org)
Date: Tue Mar 16 2004 - 07:54:12 MST
Keith,
A difference btw now and the Xanadu era is that now we have massive
amounts of RAM. When I said "massive amounts of data" I was mostly
thinking about managing highly dynamic data in multiple gigabytes (and
dozens of gigabytes ... And soon hundreds of gigabytes) of RAM
effectively. In the Xanadu era you were mostly thinking about managing
massive amounts of data on *disk*, I suppose. That is still an
important consideration for AGI, but definitively a secondary one.
-- Ben G
> At 08:25 AM 16/03/04 -0500, Ben wrote:
>
> snip
>
> >For Novamente, we chose C++ because we
> >were paranoid about scalability to deal effectively with massive
> >amounts of memory....
>
> Xanada hypertext took a similar approach for similar reasons.
>
> About 80% of the code was written in Smalltalk and autoconverted to
> C++. The rest was raw C++.
>
> The version I worked on had fixed size pointers but the
> general design had
> been worked out in variable sized numbers they called "tumblers."
>
> A high fraction of the design effort had been put into "log
> scaling" where
> access slowed as the log of the absolute size of the data
> store. The fan
> out in the (7? 8?) dimension tree was about one additional
> disk read for
> each factor of a hundred. I.e., an 8k disk block contained about 100
> pointers, most reduced to "stubs" that pointed to other disk
> blocks. The
> really active parts of the tree maintaining code were
> involved in packing
> and unpacking these disk blocks and cleaning up the mess this
> made of memory.
>
> This was a long time ago in computer terms, but the general
> problem of
> expensive, fast memory vs low cost slow memory is still with us.
>
> There are people who understand the Xanadu details much better than I
> do. The problem is that they developed a large number of
> special terms
> that make discussion nearly impossible to follow.
>
> Keith Henson
>
>
>
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