PLT Scheme is not "interpreting" code. More than that, Arc
adds a bunch of huge overheads that could make things
substantially faster. I had some patches lying around that
made things around 4-5 times faster (including the news
server).
Something that could be done for now, is to write a piece of
mzscheme code that "marshalls" the data in (utf-8-encoded)
byte-strings. Assuming that most of the 2gb is made of
strings, and that these strings are mostly ascii, this
should reduce the consumption by close to a factor of 4.
(I can imagine an interface that is transparent at the arc
level, where are strings are just passed to the backend and
retrieved from it, and the backend converts them to and
from byte strings. Later on it could change to use a FS or
a DB or whatever.)
In general, 3m is performing very well, much better than the
conservative collector plt used to use by default (the boehm
gc). As for the jit: many of the benefit of the jit are
irrelevant in Arc since it doesn't use mzscheme modules; this
is in addition to using an old mzscheme version, when the jit
was rather new -- many many improvements were done since then.
