Puzzle time!
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Puzzle time!
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Author | Message |
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Send message Joined: 26 Jun 08 Posts: 646 Credit: 476,077,208 RAC: 181,068 |
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! |
Send message Joined: 16 Apr 12 Posts: 6 Credit: 143,957 RAC: 0 |
My slight concern is that the score seems little low for these at 36. |
Send message Joined: 26 Jun 08 Posts: 646 Credit: 476,077,208 RAC: 181,068 |
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. |
Send message Joined: 16 Oct 09 Posts: 46 Credit: 849,916 RAC: 1,187 |
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. |
Send message Joined: 27 Jun 10 Posts: 1 Credit: 238,075 RAC: 0 |
The "Status of numbers page" is updated by hand, so there is a delay between finishing the sieving and updating the Status page. |
Send message Joined: 16 Oct 09 Posts: 46 Credit: 849,916 RAC: 1,187 |
Thanks I weren't aware it was updated by hand |
Send message Joined: 26 Jun 08 Posts: 646 Credit: 476,077,208 RAC: 181,068 |
I'm just waiting for the last few results to come in, and I'll start postprocessing probably later this evening. |
Send message Joined: 16 Oct 09 Posts: 46 Credit: 849,916 RAC: 1,187 |
Thanks for the update Greg |
Send message Joined: 26 Jun 08 Posts: 646 Credit: 476,077,208 RAC: 181,068 |
I started the linear algebra run this morning. It should take a bit over two weeks to finish. |
Send message Joined: 16 Oct 09 Posts: 46 Credit: 849,916 RAC: 1,187 |
Thanks Greg. May I how many CPU'S & at what speed it will take to do the linear algebra run? |
Send message Joined: 26 Jun 08 Posts: 646 Credit: 476,077,208 RAC: 181,068 |
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. |
Send message Joined: 16 Oct 09 Posts: 46 Credit: 849,916 RAC: 1,187 |
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. |
Send message Joined: 26 Jun 08 Posts: 646 Credit: 476,077,208 RAC: 181,068 |
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! |
Send message Joined: 25 Apr 12 Posts: 9 Credit: 112,044 RAC: 0 |
Hello Greg! Why the linear algebra must run on your computer, not us? |
Send message Joined: 26 Jun 08 Posts: 646 Credit: 476,077,208 RAC: 181,068 |
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. |
Send message Joined: 25 Apr 12 Posts: 9 Credit: 112,044 RAC: 0 |
Thanks! |
Send message Joined: 25 Apr 12 Posts: 9 Credit: 112,044 RAC: 0 |
What is the prograss of the lineal algebra now, Greg? |
Send message Joined: 26 Jun 08 Posts: 646 Credit: 476,077,208 RAC: 181,068 |
linear algebra completed 19054871 of 23456239 dimensions (81.2%, ETA 65h30m) We should have the factors by this weekend. |
Send message Joined: 26 Sep 09 Posts: 218 Credit: 22,841,893 RAC: 0 |
Are we there yet? |
Send message Joined: 25 Apr 12 Posts: 9 Credit: 112,044 RAC: 0 |
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) |