## yoyo@home

Neue Adresse für den Hauptserver:

**http://www.rechenkraft.net/yoyo/****Neu in Muon 1.07:**

- number of simulations reduced from 4 to 2, in avarage the wu should now need half of the time.

- muon priority changed from low to background

- displayed used cpu time is now also stored and should not fall back on a restart (at least not so much)

- some files are moved from wu to application. Wus should now be smaller and the application bigger.

- muonfiles.zip is no more sticky for wus which are now generated, so the files is automatic deleted on client side.

be prepared for the "final push for ogr challenge".

This race starts at 1. September 0:00 UTC and ends at 15. September 0:00 UTC.

The team and user with the most credits in this period is the winner.

The goal of this race is to push the OGR project a bit to its final goal. Currently more than 90% are finished and we hope that the project will still finish in 2008. We encourage each participant to enable only the cruncher application during the race and switch muon and evolution@home off.

The OGR project searches for a optimal Golomb rulers of order 25.

Happy Crunching,

yoyo

2008-10-25: yoyo@home - OGR-25: Successfully Finished

The 8-year-old OGR-25 distributed computing project has just proven conclusively that the predicted shortest 25-mark Golomb ruler is optimal. 'The total length of the ruler is 480, with marks at positions: 0 12 29 39 72 91 146 157 160 161 166 191 207 214 258 290 316 354 372 394 396 431 459 467 480. (This ruler may alternatively be expressed in terms of the distance between those positions, which is how dnetc displays them: 12-17-10-33-19-...).' 124,387 people participated in the project and two people found the shortest ruler, one on October 10, 2007 and the other on March 24, 2008.Yoyo@home user participated on this contest for

Nun offiziell, OGR-25 erfolgreich beendet.

07 November 2008 OGR-NG: new beta apps

I added beta applications for OGR-NG (ogr next generation). You must enable test applications to get them.

The effective search rate is actually more efficient as these new applications are using an improved algorithm. The new algorithm is named FLEGE (Feiri-Levet Enhanced GARSP Engine). In technical terms, the number of elements in the 'choose lookup table' has been increased from 48K to 2M elements. This optimization will significantly reduce the number of nodes that we have to search through, sometimes a node improvement of ten-fold or more.

Distributed.net estimates that OGR-26 will take much less time to complete than OGR-25 and will probably be more similar to OGR-24, in terms of computational effort. Beyond that, distributed.net is looking forward to OGR-27 and OGR-28 because the current solutions to at least one of the two is very likely not optimal. OGR-26 is on the way and must be done first since higher-order rulers depend on the proven optimality of previous ones.

In the last couple of weeks Yoyo@home's work has made large progress on an easy task, a hard task, and a very hard task. Most work on OddPerfect numbers depends on factor chains. Factor chains use the property that if a number "x" divides an odd perfect number, then the factors of a related number y also divide the odd perfect number. These factors of y can then be used to generate still more factors - so the more factors we can find the better we can build factor chains.

The easy task is finishing partial factorization that have 120-160 digits left. The hard task is factoring numbers 135-500 digits with no known factors. The very hard task is factoring the five "most wanted" numbers.

In the easy task we extended previous work on some easy numbers. The life cycle of these numbers is several stages of searching for numbers with ecm and then turning them over to factoring by the Number Field Sieve (NFS). We pushed one set of these numbers to the next stage and found some factors in the process. In the future we will give these numbers one more stage then turn them over to NFS. There is another batch of over 100 easy numbers queued up for the first stage work, and several more batches that will be queued in the future.

In the hard task we found a lot of "first known factors." Most of our records in the top 10 factors of 2009 come from this task. We should have found about 1/3 of the 50-digit factors in these numbers. In the future we will look for 50 and 55 digit factors of these numbers.

In the very hard task yoyo@home is expected to find 1/3 of the 55 digit factors in the five "most wanted" numbers. We have finished two and are 90% done with the third - no factors found yet. We will keep returning to these numbers.

I have a couple of other tasks queued up and I have plans for still more tasks in the future. I'll tell you about these tasks as we get to them in the queue.

Thanks to all the BOINC crunchers for the great progress in these tasks.

William

23 February 2009 ECM: OddPerfect

This weekend yoyo@home finished work on a batch of small composites and advanced a special project for Vanishing Fermat Quotients. We factored a dozen of the small composites. The most fun was 158 digit number for which we found two 40 digit factors. Only about 6 in 10,000 composites have two such factors, and even then we often miss one of the factors until later.

Vanishing Fermat Quotients (VFQ) happen when, for primes p and q, q2 divides pq-1. Pace Nielsen has many cases are simplified when the VFQs have two large factors, and the simplest way to verify that is to show two large factors. yoyo@home has found four new VFQ factors so far.

24 February 2009 OGR: OGR-26 finished, -27 started

OGR-26 is now officially completed. I cancelled all remaining OGR-26 wus. Wus which are now sent are OGR-27 wus.

Due to variations in complexity, distributed.net expects that OGR-27 will take significantly longer than OGR-26 did. It is difficult to provide a precise estimate but one extremely rough guess is about 7 years, assuming no increase in computing power and that the size estimation sampling reflects the entire stubspace.

There is one thing that is different with OGR-27 than with previous OGR projects: distributed.net is confident that we will discover a better ruler for OGR-27 than the one which is known to be optimal currently.

Er hat's hier beschrieben:

1) So noch nicht geschehen, Konto bei Yoyo@Home erstellen

2) Die Anwendung (Hier als gepacktes Archiv erhältlich) herunterladen und den Inhalt in

*entpacken*

**projects/www.rechenkkraft.net_yoyo**3) BOINC neu starten

4) Eine muon-Wutz herunterladen.

Ach ja, natürlich nur unter folgender Voraussetzung:

Es muss auf dem betreffenden Rechner natürlich wine installiert sein, und zwar unter usr/bin/wine

Euler wird erweitert, leider dauern die WUs jetzt um das vielfache länger, die Deadline ist etwas zu kurz gehalten, erste Tests auf Linux, nach erfolgreichen Lauf werden 510.000 WUs ausgegeben.12 June 2010 Euler625 new search

A new Euler application is now on test for Linx32 and Linux64 systems. To get the app you must enable test applications. Workunits are sometimes created for testing. The new Euler application searches now up to 250.000. There are 510.000 workunits in total. But first we need testers.