Puzzle time!

log in

Advanced search

Message boards : News : Puzzle time!

Author Message
Greg
Project administrator
Send message
Joined: 26 Jun 08
Posts: 582
Credit: 223,912,432
RAC: 19,453
Message 946 - Posted: 5 Aug 2012, 6:25:21 UTC

In the second volume of The Art of Computer Programming, Donald Knuth included a puzzle. A literary quotation is encrypted using the RSA algorithm, and we will decrypt it by factoring the public encryption key! This effort will use the lower-memory lasievee application, so more of you will be able to participate. The workunits for this challenge start with Gtaocp, and they will start going out shortly. Let's crack this as quickly as possible!

Caesar
Send message
Joined: 16 Apr 12
Posts: 6
Credit: 57,925
RAC: 0
Message 949 - Posted: 6 Aug 2012, 10:29:11 UTC - in response to Message 946.

My slight concern is that the score seems little low for these at 36.

Greg
Project administrator
Send message
Joined: 26 Jun 08
Posts: 582
Credit: 223,912,432
RAC: 19,453
Message 950 - Posted: 6 Aug 2012, 18:04:14 UTC - in response to Message 949.

This one is a lasievee task awarding 44 credits each. The somewhat easier tasks using lasieved are awarding 36 credits each. If you wish, you can disable the lasieved tasks in your NFS@Home preferences.

Speedy51
Send message
Joined: 16 Oct 09
Posts: 44
Credit: 293,342
RAC: 97
Message 961 - Posted: 29 Aug 2012, 21:57:31 UTC
Last modified: 29 Aug 2012, 22:14:57 UTC

Have all the Gtaocp tasks been sent out? Reason I'm asking is because as I write this, on the Status of numbers page It still shows TAOCP (Puzzle time!) status as Sieving. I requested tasks not so long ago and got eight 1621_73 tasks. Currently 81.28% Pushed.

Slizzer
Send message
Joined: 27 Jun 10
Posts: 1
Credit: 238,075
RAC: 0
Message 962 - Posted: 29 Aug 2012, 22:46:02 UTC - in response to Message 961.

The "Status of numbers page" is updated by hand, so there is a delay between finishing the sieving and updating the Status page.

Speedy51
Send message
Joined: 16 Oct 09
Posts: 44
Credit: 293,342
RAC: 97
Message 963 - Posted: 29 Aug 2012, 23:13:34 UTC - in response to Message 962.

Thanks I weren't aware it was updated by hand

Greg
Project administrator
Send message
Joined: 26 Jun 08
Posts: 582
Credit: 223,912,432
RAC: 19,453
Message 964 - Posted: 30 Aug 2012, 2:00:33 UTC
Last modified: 30 Aug 2012, 2:00:50 UTC

I'm just waiting for the last few results to come in, and I'll start postprocessing probably later this evening.

Speedy51
Send message
Joined: 16 Oct 09
Posts: 44
Credit: 293,342
RAC: 97
Message 965 - Posted: 30 Aug 2012, 2:19:22 UTC

Thanks for the update Greg

Greg
Project administrator
Send message
Joined: 26 Jun 08
Posts: 582
Credit: 223,912,432
RAC: 19,453
Message 966 - Posted: 31 Aug 2012, 7:37:38 UTC - in response to Message 965.
Last modified: 31 Aug 2012, 7:37:47 UTC

I started the linear algebra run this morning. It should take a bit over two weeks to finish.

Speedy51
Send message
Joined: 16 Oct 09
Posts: 44
Credit: 293,342
RAC: 97
Message 967 - Posted: 2 Sep 2012, 6:53:17 UTC - in response to Message 966.

Thanks Greg. May I how many CPU'S & at what speed it will take to do the linear algebra run?

Greg
Project administrator
Send message
Joined: 26 Jun 08
Posts: 582
Credit: 223,912,432
RAC: 19,453
Message 968 - Posted: 2 Sep 2012, 20:31:42 UTC - in response to Message 967.

The LA is running on eight computers, each containing a 2.4GHz Core 2 Quad processor and DDR2 memory, connected by Infiniband. It's currently 19.8% done with 280 hours remaining.

Speedy51
Send message
Joined: 16 Oct 09
Posts: 44
Credit: 293,342
RAC: 97
Message 969 - Posted: 2 Sep 2012, 21:48:13 UTC - in response to Message 968.
Last modified: 2 Sep 2012, 21:48:47 UTC

That is some serious processor power 78.8Ghz. I gather all the output data is sent to 1 hard drive or location? Once you have all the post processed data how is it stored How much space in total have you used with completed work from the project? Thanks for taking the time to answer my questions.

Greg
Project administrator
Send message
Joined: 26 Jun 08
Posts: 582
Credit: 223,912,432
RAC: 19,453
Message 970 - Posted: 2 Sep 2012, 22:55:34 UTC - in response to Message 969.
Last modified: 2 Sep 2012, 22:57:43 UTC

The files for this factorization total ~49 GB. That consists of ~40 GB of relations from NFS@Home sievers stored in a single plain text file, a ~9 GB binary matrix file, and miscellaneous smaller files.

For the largest so far, 2,1061-, the files total 125 GB including an 86 GB text file containing the relations and a 37 GB binary matrix file.

Once we have completed a factorization, I typically delete the associated files. However, I have saved the recent largest factorizations:

58G ./6p379
111G ./2p997
125G ./2m1061
57G ./5p433
118G ./2m1031
113G ./5m409
58G ./3m607
636G .

6p379, 5p433, and 3m607 are smaller because I've compressed the text relations file. I just haven't bothered to do that for the others. Fortunately, disk space is now cheap!

tuankiet65
Send message
Joined: 25 Apr 12
Posts: 9
Credit: 112,044
RAC: 0
Message 971 - Posted: 3 Sep 2012, 2:16:27 UTC

Hello Greg!

Why the linear algebra must run on your computer, not us?

Greg
Project administrator
Send message
Joined: 26 Jun 08
Posts: 582
Credit: 223,912,432
RAC: 19,453
Message 972 - Posted: 3 Sep 2012, 2:52:39 UTC - in response to Message 971.

The linear algebra algorithm requires nearly constant communication of a large amount of data between all of the computers used in the calculation, so it must be done on a local cluster connected with a high-speed network. The Infiniband network that the cluster has provides 10 Gbit/s bandwidth in each direction for each computer with a communication latency less than 2 microseconds.

tuankiet65
Send message
Joined: 25 Apr 12
Posts: 9
Credit: 112,044
RAC: 0
Message 973 - Posted: 5 Sep 2012, 4:08:45 UTC - in response to Message 972.

Thanks!

tuankiet65
Send message
Joined: 25 Apr 12
Posts: 9
Credit: 112,044
RAC: 0
Message 977 - Posted: 11 Sep 2012, 9:42:28 UTC

What is the prograss of the lineal algebra now, Greg?

Greg
Project administrator
Send message
Joined: 26 Jun 08
Posts: 582
Credit: 223,912,432
RAC: 19,453
Message 978 - Posted: 11 Sep 2012, 19:09:20 UTC - in response to Message 977.

linear algebra completed 19054871 of 23456239 dimensions (81.2%, ETA 65h30m)

We should have the factors by this weekend.

Profile Carlos Pinho [TSBTs Pirate]
Volunteer moderator
Send message
Joined: 26 Sep 09
Posts: 162
Credit: 7,723,521
RAC: 0
Message 981 - Posted: 15 Sep 2012, 12:00:42 UTC

Are we there yet?

tuankiet65
Send message
Joined: 25 Apr 12
Posts: 9
Credit: 112,044
RAC: 0
Message 982 - Posted: 15 Sep 2012, 15:10:28 UTC - in response to Message 981.

I can take a sleep tonight and there is the result at tommorow morning(sorry, I am in vietnam and it's 10 o'clock now, GMT+7)

Message boards : News : Puzzle time!


Home | My Account | Message Boards