[plans] distributed.net .plan update

plans at nodezero.distributed.net plans at nodezero.distributed.net
Thu Aug 28 01:00:04 EDT 2003


distributed .plan updates in the last 24 hours:
---

decibel :: 26-Aug-2003 19:20 CDT (Tuesday) ::

As indicated on the stats page, we have now searched every OGR-24 stub that
we distributed to the network. There is still more work to be done before we
can declare OGR-24 finished, however.

(If you're unfamiliar with how OGR searches work, you might want to visit
http://n0cgi.distributed.net/faq/cache/281.html)

The issue is that the stub generation for both OGR-24 and -25 has been
constrained very tightly; the 70 mark constraint that is in use is more
appropriate for OGR-21.  In all likelihood if a shorter ruler exists it
would exist in the space we've already searched.  However, we are not
confident that the present search space is sufficiently exhaustive for
scientific purposes.  We've completed the pragmatic search but still have to
fill in the "brute" part of "brute force".

One of the challenges inherent in OGR is that it's not possible to predict
beforehand how long any given stub will take to test.  Accordingly, the
total burden of a particular ruler's search is not predictable.  While
counting the number of remaining stubs is easy it is not a measure of the
amount of work which remains, especially since the remaining stubs are
smaller than the stubs that have been searched to-date. It is safe to say
that we're well past 50%, and we're most likely past 80 or 90%.

Obviously, finding out we're still not done with OGR-24 is a disappointment
to all of us. It's important to realize that the work that's been done thus
far is valid and had to be done. Likewise, while the 77% shown for OGR-25
right now is also far too optimistic, the OGR-25 work being done is
perfectly valid.

We still have a considerable number of small stubs (length >70 at the 6th
mark) which we have not distributed to the network. This is because most of
these stubs would take only minutes or even seconds to complete. Once we've
determined how much work is left to do we will be able to decide how to
complete it. An early estimate indicates that the distributed.net staff
could check the remaining stubs. If this is not the case we would distribute
the work to the network, but we can't do this until we can 'combine stubs'
so that many stubs that would take minutes to complete could be grouped
together. This is the only way the network at large could reasonably process
these minute-long stubs.

We are currently working on an improved OGR algorithm. Because of the work
verification process we use, we can not mix the results of the new algorithm
with the results from the current algorithm. We will use the improved
algorithm to finish OGR-24. Once we have checked all OGR-25 stubs with an
initial length <=70, we will also use the new algorithm on OGR-25.



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