Mathworld surrenders
 

[quote]
mersenne40.txt and mersenne40.zip currently unavailable

Due to extremely high demand for the file containing the decimal digits of the new Mersenne prime, this file is temporarily unavailable. We apologize for the inconvenience, and encourage readers to check back at a later time.

[url]http://mathworld.wolfram.com/news/2003-12-02/mersenne/mersenne40.html[/url]

[/quote]

:surrender :surrender :surrender

If they couldn't handle the bandwidth, there's no way we could have.

I'd seriously suggest [b]never making a decimal-digit-expansion available again[/b] for any new Mersenne prime.

Most people probably click on the link and just sit there while it downloads the whole thing... and then never scroll past the first few pages (or the first page, period).

If they want to look up how many times their phone number or Social Security number or other number sequence occurs within the decimal-digit expansion, we might create a CGI interface for that. But even that might overtax resources in terms of CPU time, even if you precompute all the answers for sequences of N digits or less.

If we ever make a decimal-digit expansion of a Mersenne prime available again, it should only be in BitTorrent form.

For those of you unfamiliar with that application, it's a P2P program where clients download a file not only from the server, but download discontinuous pieces of the file [i]from each other[/i], greatly reducing the load on the server. It's a way of handling massive downloading of files, especially suitable when there's a sudden high demand.

BitTorrent is a relatively new thing, most people haven't heard of it or used it. Perhaps by the time the next prime is found, that will no longer be the case.

Keep the decimal expansions, just don't post the link in a prominent place.

Put a note beside the link that mentions that it will take a while to load.

Re: Mathworld surrenders
 

[QUOTE][i]Originally posted by GP2 [/i]
[B]
I'd seriously suggest [b]never making a decimal-digit-expansion available again[/b] for any new Mersenne prime.
[/B][/QUOTE]

Or perhaps only include the first and the last 10.000 decimals in the file. That would still give the impression of "huge".

And then Torrent the whole file like you suggested and/or make it available on mersenne.org only some weeks after the discovery.

Are there any ways of calculating the number in javascript in a reasonable amount of time? In that case we could just send over the exponent along with the javascrip-program and let each client do the expansion themself.:razz:

[QUOTE][i]Originally posted by I_like_tomatoes [/i]
[B]Put a note beside the link that mentions that it will take a while to load. [/B][/QUOTE]

That's not the problem.

When a lot of users are trying to download the same large file at the same time, two undesirable things happen:

1) The entire website slows down, sometimes to the point of rendering it unusable. It's a data traffic jam.

2) It costs the website owner money. For most low-volume websites, the website owner gets a certain quota of data transfer that's covered by a fixed monthly fee... but if heavy downloading causes that quota to be exceeded, the website operator has to pay for every extra gigabyte.

Why not just provide users with a link to a simple software utility (hopefully no more than a few kB in size) that allows them generate the decimal printout on their own computer?

I would really like to have aprogram that can also print out the current exponent im working on if I punch it in.
I want to see what a 10mil looks like ! :shock:

[url]http://www.apfloat.org/apfloat/mprintc5.zip[/url]

Takes 7 seconds on a 2.67GHz P4...

[code]C:\Documents and Settings\Mike\Desktop>ls -l 20996011.*
-rwx------ 1 Mike None 6320432 Dec 5 11:15 20996011.txt
-rwx------ 1 Mike None 2965894 Dec 5 11:15 20996011.txt.gz
-rwx------ 1 Mike None 2722533 Dec 5 11:15 20996011.txt.bz2[/code]

Instead of the decimal digit expansion, provide only the binary digit expansion in zipped form. Zip can compress a long string of '1's quite efficiently. :razz:

[b]Landon Curt Noll[/b] has a couple of utilities that might be of interest:

[url=http://www.isthe.com/chongo/tech/comp/calc/index.html]calc[/url] Compute decimal values of primes
and
[url=http://www.isthe.com/chongo/tech/math/number/number.html]Number[/url] Compute English names of primes

PM

[QUOTE][i]Originally posted by ewmayer [/i]
[B]Why not just provide users with a link to a simple software utility (hopefully no more than a few kB in size) that allows them generate the decimal printout on their own computer? [/B][/QUOTE]

Hmmm... maybe that "simple software utility" should be Prime95 itself. It prints the digits... and secretly installs itself in the background. :devil:

Maybe printing an endless stream of digits of M40 is what a screensaver version of Prime95 could do...

We could separate it into chunks of a thousand digits, and hope that people aren't dedicated enough to look at all of them.

[url]http://opteron.mersenneforum.org/2^20996011-1.zip[/url]

No bandwidth cap, but I bet it is slow!

Just for fun...

[code]C:\Documents and Settings\Mike\Desktop>mprint 20996011 2 > binary.txt
Total time 1 seconds

C:\Documents and Settings\Mike\Desktop>zip binary.zip binary.txt
adding: binary.txt (deflated 100%)

C:\Documents and Settings\Mike\Desktop>ls -l binary.*
-rw-r--r-- 1 Mike None 20996013 Dec 5 11:51 binary.txt
-rw-r--r-- 1 Mike None 20524 Dec 5 11:51 binary.zip[/code]

I dont think I'm quite clear on how to use mprint...i click on the exe but the program doesnt work

<----- noob:redface:

Also,that Calc program looks way to complicated to even install rofl

[QUOTE][i]Originally posted by Xyzzy [/i]
[B]Just for fun...

[code]C:\Documents and Settings\Mike\Desktop>mprint 20996011 2 > binary.txt
Total time 1 seconds

C:\Documents and Settings\Mike\Desktop>zip binary.zip binary.txt
adding: binary.txt (deflated 100%)

C:\Documents and Settings\Mike\Desktop>ls -l binary.*
-rw-r--r-- 1 Mike None 20996013 Dec 5 11:51 binary.txt
-rw-r--r-- 1 Mike None 20524 Dec 5 11:51 binary.zip[/code] [/B][/QUOTE]

By writing the prime in binary form, you're not doing anything fancier than what the Mersenne prime exponent tells you. So getting it down to 20kB isn't even close to degree of compression one gets simply by writing

20996011

or even better, replacing those 8 ascii bytes with the 25 bits needed to write that number in binary form. Until the precise position amongst the set of Mersennes is known (it could be M#41 for all we know), 25 bits is a low as you can go. If we establish that it's (say) the 40th M-prime, then we could specify it exactly using just 6 bits (# of bits needed to write '40'). Of course to actually calculate the number a priori from those 6 bits, we'd have to do LL tests of all the prime expnents in order until we find the 40th such which yields a Mersenne prime - that would be trading one godawfully large amount of computation for a savings of a mere 19 bits. :ermm:

[QUOTE][i]Originally posted by Quacky [/i]
[B]I dont think I'm quite clear on how to use mprint...i click on the exe but the program doesnt work[/B][/QUOTE]There is a readme file in the zip... Also, you run it from the command line... (Look at my example above!)

Given that Slackware ISOs are only "officially" available via BitTorrent downloads as of the 9.1 release, I suspect it'll get a lot more widespread over the next year.

It's not new technology - Kaaza and BearShare (and I believe Gnutella) all have beed doing the "get pieces from multiple sources" stuff for a while now. Implimentation is somewhat different, though....

mprint indeed creates the decimal expansion in 7 seconds but Notepad fails to open that 6M file (possibly because it has no EOL/CR chars).

How about just providing some basic stats about the number,
a few leading and a few ending digits (or a few hunderd of each), how many times each digit appears etc.

Notepad opens it fine here... Wordpad will open it too...

I wonder what servers Primenet has. I know the forum has an Opteron.

[QUOTE][i]Originally posted by clowns789 [/i]
[B]I wonder what servers Primenet has. I know the forum has an Opteron. [/B][/QUOTE]

Actually, the processor is rather unimportant. Any modern processor can deliver more content than the interconnection can handle.

So the important question to ask is "how is .... connected to the 'net?"

Richard

[QUOTE][i]Originally posted by clowns789 [/i]
[B]I wonder what servers Primenet has. I know the forum has an Opteron. [/B][/QUOTE]Actually, the forum is not on the Opteron... The web server for the forum is on a 1.5GHz P4 with 1GB of RAM... I don't know what the database server is...

[url]http://www.pair.com/about/data_center_tour/[/url]

There was 2 bytes of crap at the end of the m40 link I posted above... The new link is:

[url]http://opteron.mersenneforum.org/m40.zip[/url]

BTW, I have everything set up we need to run a Bittorrent in the future, except for the tracker... If someone can figure out how to get a tracker working we can Bittorrent any file we need...

I have a tracker :).

When making the file, put this in the tracker/announce URL:

[url]http://andrewhitchcock.org:6969/announce[/url]

Also, if you e-mail me with some stats for each file (filesize in bytes, filename, and the .torrent you just created), I can add them to the database at [URL=http://torrent.andrewhitchcock.org]my tracker page[/URL].

Andrew

[url]http://opteron.mersenneforum.org/m40.zip.torrent[/url]

This should download m40.zip via Bittorrent... The file size is 2966003 bytes...

If for some reason it doesn't work, you can download the zip file from the Opteron and use that to seed your Bittorrent client:

[url]http://opteron.mersenneforum.org/m40.zip[/url]

I think it would be cool, as an experiment, if we could get 20 or more people to "sign on" as seeds and see how fast this works!

If you do decide to help, please post here...

Here is where you can download Bittorrent:

[url]http://bitconjurer.org/BitTorrent/download.html[/url]

Here is an experimental client that allows bandwidth limiting...

[url]http://ei.kefro.st/projects/btclient/[/url]

Set it for dialup/ISDN and it uses only 8kbps...

Ok - i started leeching it 10 minutes ago and are seeding now. I try to keep the seed active for the next hours.

[URL=http://www.3dgamers.com/]Mayor game sites[/URL] use torrents a lot with success. Nice technology.

btw: i need one off these nice [URL=http://andrewhitchcock.org/index.pl?page=fixcomputer]t-shirts[/URL] :grin:

Okay, cool. I am downloading it now. I'll seed it from now on, with the rest of the files I seed.

I also added the metadata, so now it appears on my torrent page. Feel free to use the tracker for other Mersenne related data files.

The t-shirt can be had from [url]http://www.thinkgeek.com/.[/url] Just to make sure you didn't think I sold them, I've talked to a lot of people that have had that impression.

Andrew

[url]http://opteron.mersenneforum.org/perfect6.zip.torrent[/url]

If for some reason it doesn't work, you can download the zip file from the Opteron and use that to seed your Bittorrent client:

[url]http://opteron.mersenneforum.org/perfect6.zip[/url]