Mersenne Digest        Saturday, June 17 2000        Volume 01 : Number 748




----------------------------------------------------------------------

Date: Thu, 15 Jun 2000 22:59:27 +0200
From: "Martijn Kruithof" <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Assignment "stolen"

Hi,

It is a first time test, I do not care to run some double checks, 
the problem however is 
that I cannot even put double-check in the worktodo file, the 
assignment will be deleted as soon as the primenet server is 
contacted. It says it already has a result for the exponent.
I think I will back the files up and make it a 
double-check assignment after the next database sync.
(Well before the values are assigned again by primenet.)
When an unassigned exponent gets reported PrimeNet will
assign it to the one reporting to work on the exponent.

Anybody knows when the next database sync will be?

Kind Regards, Martijn


- ----- Original Message ----- 
From: "Brian J. Beesley" <[EMAIL PROTECTED]>
To: "Martijn" <[EMAIL PROTECTED]>
Sent: Thursday, June 15, 2000 9:12 PM
Subject: Re: Mersenne: Assignment "stolen"


> On 15 Jun 00, at 17:31, Martijn wrote:
> 
> > I just saw that an exponent I am testing (due in about 
> > 20 days) sudennly was removed from my account report. 
> > When looking in the cleared exponents list, "my" 
> > exponent is listed as cleared by milbournea (no 
> > offence). Should I stop testing this exponent or should 
> > I still await the final result and return it (i.e. 
> > making a double-check unnecessary / let it be the 
> > double check.) 
> 
> I take it you had a first-test assignment.
> 
> If so I'd let it complete. This will be accepted by PrimeNet & will 
> eventually save someone else running a double-check.
> 
> If, however, your assignment was a double-check, there seems little 
> point in continuing :(
> 
> > When returning, will the LL time be credited?
> 
> I don't think so. If this really worries you then stop the program & 
> mail me the Pnnnnnnn file (will shrink by a useful amount if you 
> compress it using zip or tar z) & I'll finish the run off for you. 
> Then delete the offending line from worktodo.ini & restart the 
> program.
> 
> 
> Regards
> Brian Beesley
> 

_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Thu, 15 Jun 2000 18:55:52 -0400
From: George Woltman <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Assignment "stolen"

Hi Martijn,

At 10:59 PM 6/15/00 +0200, Martijn Kruithof wrote:
>the problem however is
>that I cannot even put double-check in the worktodo file, the
>assignment will be deleted as soon as the primenet server is
>contacted.

If you leave your worktodo.ini file alone, everything will be OK.
That is, your worktodo.ini should read "Test=exponent,64,1"
The server will accept your result but probably will not give you
CPU credit.

There is no difference between a double-check and a first-time test!!
Prime95 merely lowers your probability of finding a Mersenne prime
if it is told this is a double-check.  Other than that, the Lucas-Lehmer
test is the same.

If you have any further questions, just email me.

Regards,
George

_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Thu, 15 Jun 2000 22:11:58 +0200
From: Lem Novantotto <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Assignment "stolen"

On Thu, 15 Jun 2000 17:31:48 +0200, in Mersenne_mailing_list you
wrote:
>I just saw that an exponent I am testing (due in about 
>20 days) sudennly was removed from my account report. 
>When looking in the cleared exponents list, "my" 
>exponent is listed as cleared by milbournea (no 
>offence). Should I stop testing this exponent or should 
>I still await the final result and return it (i.e. 
>making a double-check unnecessary / let it be the 
>double check.) 
>When returning, will the LL time be credited?

Hi!
Almost the same thing happened to me some months ago. 5 days before
sending the result of a LL test, everything was fine. When I sent the
result, I got an error saying that the exponent wasn't assigned to me
(an then no credit... which made change my account, to see if
something had gone wrong with it). But some days after, answering my
question, Primenet folks told me that the exponent had been reassigned
to me after 60 days of no communication from the previous tester: but
he had sent the result just before me, so the exponent was considered
cleared. But why my test wasn't seen as a double checking, then? I
dunno'.
- -- 
Bye.
      Lem
- ---------- 'CLOCK is what you make of it' ----------
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Thu, 15 Jun 2000 22:51:56 EDT
From: "Nathan Russell" <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Assignment "stolen"

>From: Lem Novantotto <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>CC: [EMAIL PROTECTED]
>Subject: Re: Mersenne: Assignment "stolen"
>Date: Thu, 15 Jun 2000 22:11:58 +0200
>
>Hi!
>Almost the same thing happened to me some months ago. 5 days before
>sending the result of a LL test, everything was fine. When I sent the
>result, I got an error saying that the exponent wasn't assigned to me

(snip)

>Primenet folks told me that the exponent had been reassigned
>to me after 60 days of no communication from the previous tester: but
>he had sent the result just before me, so the exponent was considered
>cleared. But why my test wasn't seen as a double checking, then? I
>dunno'.
>--
>Bye.
>       Lem

IIRC, PrimeNet sends out assignments either as first-time testing or as 
double-checking.  Since the previous tester sent in his result in the middle 
of yours, your machine still thought it was doing a first-time test.  In the 
next month or two, George and the PrimeNet folks will do a resynch, which 
means in part that they will look for where weird stuff like that happened.  
That is when it'll be recognized that the double-check was complete.

You will still get PrimeNet credit for the test, and will get credit on 
George's page once the update takes place.

BTW, I myself occasionally grab reissued double-checking assignments from 
PrimeNet.  In the case of these, a redundant check accomplishes nothing.

Nathan
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 00:53:33 -0700
From: Stefan Struiker <[EMAIL PROTECTED]>
Subject: Mersenne: Desperately Seeking Faster Iron

TeamG:

With first-time L-L checking sliding toward a lunar month on an "old" 1GHz Athlon,
we wonder how the Willamette and Itanium might further The Cause.  Anyone
have guessimates on the numbers for these two, say at 1GHz?

Who, Me In A Hurry?
Stefanovic



_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 01:40:26 -0700
From: "Jim Howell" <[EMAIL PROTECTED]>
Subject: Mersenne: Factoring

This is a multi-part message in MIME format.

- ------=_NextPart_000_0023_01BFD733.D8A291E0
Content-Type: text/plain;
        charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

[Wed 14 Jun 2000, Paul Leyland writes]

Today I found this number 3756482676803749223044867243823 with ECM and
B1=3D10,000.  It has two factors, each of 16 digits, which could *not* =
have
been found by trial division in any reasonable time.

- -------------

I use a program called "factor.exe", which uses several factoring =
methods.  It factors the above number within several seconds.  (For this =
number, the factors are found with the P-1 method.)  In case anyone is =
interested, the factors are  1483398061194277 and 2532349728015299.

This program runs on Windows, and can be downloaded from Chris =
Caldwell's main page, at:

http://www.utm.edu/research/primes

Go down to section 4, (Software), and look for "factor.exe", described =
as a DOS program, but it actually runs in a Command Window on Windows 95 =
and later, and (probably) not under actual DOS.  I find "factor.exe" =
quite useful for factoring small numbers (it will accept numbers up to =
about 130 digits).
- --Jim


- ------=_NextPart_000_0023_01BFD733.D8A291E0
Content-Type: text/html;
        charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content=3D"text/html; charset=3Diso-8859-1" =
http-equiv=3DContent-Type>
<META content=3D"MSHTML 5.00.2314.1000" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>[Wed 14 Jun 2000, Paul Leyland =
writes]</FONT></DIV>
<DIV><FONT face=3DArial size=3D2><BR>Today I found this number=20
3756482676803749223044867243823 with ECM and<BR>B1=3D10,000.&nbsp; It =
has two=20
factors, each of 16 digits, which could *not* have<BR>been found by =
trial=20
division in any reasonable time.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>-------------</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>I use a program called "factor.exe", =
which uses=20
several factoring methods.&nbsp; It factors the above number&nbsp;within =
several=20
seconds.&nbsp; (For this number, the factors are found with the P-1=20
method.)&nbsp; In case anyone is interested, the factors are&nbsp;=20
1483398061194277 and 2532349728015299.<BR></FONT></DIV>
<DIV><FONT face=3DArial size=3D2>This program runs on Windows, and can =
be downloaded=20
from Chris Caldwell's main page, at:</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2><A=20
href=3D"http://www.utm.edu/research/primes">http://www.utm.edu/research/p=
rimes</A></FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Go down to section 4, (Software), and =
look for=20
"factor.exe", described as a DOS program, but it actually runs in a =
Command=20
Window on Windows 95 and later, and (probably) not under actual =
DOS.&nbsp; I=20
find "factor.exe" quite useful for factoring small numbers (it will =
accept=20
numbers up to about 130 digits).</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>--Jim</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>&nbsp;</DIV></FONT></BODY></HTML>

- ------=_NextPart_000_0023_01BFD733.D8A291E0--

_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 08:10:06 EDT
From: "Nathan Russell" <[EMAIL PROTECTED]>
Subject: Mersenne: Pointers on farming

Hi all,

In order to learn hardware before leaving for college, I have taken a 
full-time job at a local computer recycling place.  Since I will be 
attending college on a rather nice scholarship, I will have more money than 
I am likely to need in the immediate future; through my work, I will also 
recieve a 15-30% discount on hardware beyond the wholesale prices.

I am considering setting up 1-3 rather slow (P2-250 or below) Debian boxes 
in my parents' basement and using them for some combination of QA factoring 
and 'regular' double-checking assignments.

I would have to give them assignments via sneakernet, as my family uses 
dialup internet and I doubt they would want the phone tied up at random 
hours  as machines dial in to request new assignments.  Also, it would be 
tough, to say the least, to run phone cables down from the nearest jack, 
which is about fifty feet from the counter I envision, and down a flight of 
stairs to boot.

My questions for the list:

1. How difficult is it to set up Debian on a box of known specs?  Also, is 
it plausible that a box would run without intervention from August to 
December?
2. Which type of processor, memory etc will give the most bang for the buck? 
  We rarely see anything beyond P2-250's, so I would have to pay retail for 
that.
3. How could I get double-checking assignments that are big enough not to 
delay the project before I can report results in mid-December, and that will 
not require constant checkins before then (I am not sure that I will be home 
between about August 22 and the second week of December; we sometimes go to 
one of my cousins' houses for Thanksgiving).  Email from George is the 
obvious option; are there any others?

Regards,
Nathan
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 10:33:20 -0400
From: George Woltman <[EMAIL PROTECTED]>
Subject: Mersenne: Search for primitive trinomial

Hi all,

        Richard Brent is using Mersenne primes in generating random 
numbers.  However, he needs help in finding "primitive trinomials" first.
If you would like to help him search or are just curious as to what he is
doing, visit http://web.comlab.ox.ac.uk/oucl/work/richard.brent/trinom.html

Regards,
George

_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 08:24:13 -0700
From: Eric Hahn <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Desperately Seeking Faster Iron

Stefan Struiker wrote:
>With first-time L-L checking sliding toward a lunar month on an
>"old" 1GHz Athlon, we wonder how the Willamette and Itanium might
>further The Cause.  Anyone have guessimates on the numbers for
>these two, say at 1GHz?

I'd guessimate about 17.5-18 days for an exponent around
10,000,000, for the first Willamette(s) which is supposed
to debut at 1.4GHz...

Then again, according to my calcs, a 1GHz Athlon should finish
the same exponent in about 17.5-18 days...

Go figure!

Eric


_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 16:47:37 +0200
From: "Steinar H. Gunderson" <[EMAIL PROTECTED]>
Subject: Mersenne: Re: Factoring

On Fri, Jun 16, 2000 at 01:40:26AM -0700, Jim Howell wrote:
>This program runs on Windows, and can be downloaded from Chris Caldwell's main page, 
>at:

Just wanted to add that there is a Linux version as well -- I'd guess it's
available at the same place.

It didn't factor your number using P-1, though -- it had to go through 11
ECM curves in my case. Guess it's just bad luck or something :-)

/* Steinar */
- -- 
Homepage: http://members.xoom.com/sneeze/
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 16:52:24 +0200
From: "Steinar H. Gunderson" <[EMAIL PROTECTED]>
Subject: Mersenne: Re: Pointers on farming

On Fri, Jun 16, 2000 at 08:10:06AM -0400, Nathan Russell wrote:
>1. How difficult is it to set up Debian on a box of known specs?

Not very difficult, if you've installed Linux before.

>Also, is 
>it plausible that a box would run without intervention from August to 
>December?

Yes. Linux in general is very stable.

>2. Which type of processor, memory etc will give the most bang for the buck? 
>  We rarely see anything beyond P2-250's, so I would have to pay retail for 
>that.

Sorry, don't know :-( Divide MHz by price (more or less -- the multiplier
setting of the CPU would also count in here) -- higher is better. Remember
that a few quicker machines would perhaps be an idea (unless you want the
machines for something else later, that is!), as every machine requires some
RAM, a power supply, some disk space etc.

>3. How could I get double-checking assignments that are big enough not to 
>delay the project before I can report results in mid-December, and that will 
>not require constant checkins before then (I am not sure that I will be home 
>between about August 22 and the second week of December; we sometimes go to 
>one of my cousins' houses for Thanksgiving).  Email from George is the 
>obvious option; are there any others?

What about using the `Vacation' option? If that won't give you enough exponents,
you can use the MaxExponents= setting (see undoc.txt) to get more.

/* Steinar */
- -- 
Homepage: http://members.xoom.com/sneeze/
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 22:54:02 +0200
From: Yann Forget <[EMAIL PROTECTED]>
Subject: Mersenne: Factoring with ECM

Hi,
Could you explain this to me ?
I am factoring Fermat numbers with ECM.
Is this relevant in this case ?

Thanks in advance,
Yann

> Paul Leyland said:
As long as the coefficients of the curve and the starting point are
recorded, we can re-run exactly the same computation, with the small
primes
curtailed as in the p-1 case, on the same curve and the number c.  It's
because my software doesn't normally output the curve and starting point
used that the idea hadn't occurred to me.

Paul
- -- 
Ionix Services, les services r�seaux d'aujourd'hui
http://www.ionix-services.com/
Tel 04 38 12 38 90
Fax 04 38 12 38 94
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Sat, 17 Jun 2000 05:37:06 -0400
From: "Larry Murray" <[EMAIL PROTECTED]>
Subject: Mersenne: LOST NUMBERS

Hi ALL:
         This is a letter I sent asking what happened to the prime numbers I was 
working on. I am posting it here to remind people who are doing 10million digit 
numbers to log on at least once a month to update there page so this doesn't happen to 
them

Hi Lawrence, 
I reviewed the server logs regarding these exponents and what has happened 
is the timeout period(60 days) that the server will wait prior to releasing 
them had expired. This is tied to your contacting the server so that Prime95 
can update the expected completion date, you missed the window by 3 days. 

Is all your hard work(and subsequent credit) lost? No, although the server 
has already re-assigned them to another account it will still accept the 
results and properly credit your account for the completed work. 

Regards, 
Brad Bernard 
PrimeNet Support Engineer 

- -----Original Message----- 
From: Lawrence Murray [mailto:[EMAIL PROTECTED]] 
Sent: Friday, June 16, 2000 5:15 AM 
To: [EMAIL PROTECTED] 
Subject: not assigned 


Hi my name is Lawrence Murray and I have been running 2 10million 
numbers since september of last year 33220001 & 33219313 one is 49% done 
and the other is 63% done. when I went to upload the latest results it 
said that these numbers are not assigned to me I would like to know why 
they were taken away from me. My duel pentium 600mhz processor computer 
have been working on these numbers and nothing else for 9 months and I 
am not willing to loose the credit for all that work my computers have 
put into this. could you please straighten this out right away thank you 
LP Murray 

_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Sat, 17 Jun 2000 15:38:02 +0200
From: Lem Novantotto <[EMAIL PROTECTED]>
Subject: Re: Mersenne: LOST NUMBERS

On Sat, 17 Jun 2000 05:37:06 -0400, in Mersenne_mailing_list you
wrote:
>Is all your hard work(and subsequent credit) lost? No, although the server 
>has already re-assigned them to another account it will still accept the 
>results and properly credit your account for the completed work. 

Hi!
I think it would be nice to post the mersenne numbers you're still
working to, and that have been reassigned, so, hopefully, the new
tester can read them and stop his testing. Otherwise HE is going to
loose time and credit.
- -- 
Bye.
      Lem
- ---------- 'CLOCK is what you make of it' ----------
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Fri, 16 Jun 2000 19:01:47 +0100
From: Tony Forbes <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Re: Pointers on farming

Steinar H. Gunderson <[EMAIL PROTECTED]> writes
>>2. Which type of processor, memory etc will give the most bang for the buck? 
>>  We rarely see anything beyond P2-250's, so I would have to pay retail for 
>>that.
>

Here is a calculation I did about six months ago

AMD K6/2 500 MHz (plus fan)        45 pounds Sterling
Super-socket-7 motherboard         45 pounds
32M 100Mhz RAM                     20 pounds
Old 486 to put it in                1 pound

To this one should add the cost of electricity. The computer draws about
40 Watts. A Watt costs about 0.60 pounds per year. For, say, three years
of computation, add

120 Watt-years of electricity      72 pounds
                                  ----------
Total                             183 pounds

That's 36.6 pence per MHz; or, since I am writing it off after three
years, 0.389 pence per trillion cycles.

- -- 
Tony
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Sat, 17 Jun 2000 17:28:52 +0200 (CEST)
From: Henrik Olsen <[EMAIL PROTECTED]>
Subject: Re: Mersenne: LOST NUMBERS

On Sat, 17 Jun 2000, Lem Novantotto wrote:
> On Sat, 17 Jun 2000 05:37:06 -0400, in Mersenne_mailing_list you
> wrote:
> >Is all your hard work(and subsequent credit) lost? No, although the server 
> >has already re-assigned them to another account it will still accept the 
> >results and properly credit your account for the completed work. 
> 
> Hi!
> I think it would be nice to post the mersenne numbers you're still
> working to, and that have been reassigned, so, hopefully, the new
> tester can read them and stop his testing. Otherwise HE is going to
> loose time and credit.
Since first and double checks are credited equally(as far as I know),
both should get credited with the same amount of work except for counting 
tests.

Time spent on a doublecheck is only wasted if it's turned into a
triplecheck and all three results agree.

- -- 
Henrik Olsen,  Dawn Solutions I/S       URL=http://www.iaeste.dk/~henrik/
 ZOOLOGY, n. 
   The science and history of the animal kingdom, including its king, the
   House Fly (Musca maledicta).    The Devil's Dictionary, Ambrose Bierce.


_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Sat, 17 Jun 2000 17:03:26 +0100
From: "Michael Bell" <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Re: Pointers on farming

>
>Here is a calculation I did about six months ago
>
>AMD K6/2 500 MHz (plus fan)        45 pounds Sterling
>Super-socket-7 motherboard         45 pounds
>32M 100Mhz RAM                     20 pounds
>Old 486 to put it in                1 pound
>
>To this one should add the cost of electricity. The computer draws about
>40 Watts. A Watt costs about 0.60 pounds per year. For, say, three years
>of computation, add
>
>120 Watt-years of electricity      72 pounds
>                                  ----------
>Total                             183 pounds
>
>That's 36.6 pence per MHz; or, since I am writing it off after three
>years, 0.389 pence per trillion cycles.
>

Warning on K6's:  As far as GIMPS is concerned they're not too good, because
the FPU is about half the speed of the Intel Pentium FPU.  (If you run RC5
then they're as good, if not better, because they have very good integer
units).

This means that on GIMPS effectively you get 250MHz, so you get 73.2 pence
per MHz.  So providing you can find an AT form factor PII/Socket 370
Motherboard (which I managed to do last December), you can put a Celeron in
instead, although a 500MHz Celeron costs about �85 instead of 45, you get
back to your 37pence/MHz figure.  Also note memory prices have gone up, so
32M now costs about �40-50!!  Maybe this is the first time in recent history
the price of a computer has stabilised??

Michael Bell.

_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Sat, 17 Jun 2000 09:52:30 -0700
From: Stefan Struiker <[EMAIL PROTECTED]>
Subject: Mersenne: Factoring Assignments:  Are They Always "First-Time?"

TeamG:

When a requested factoring assignment is listed with, say, 52 in an account log,
does this mean it has been factored to 52 bits, but  _without_ success?
Or could a factor have already been found in some cases, but less than
52 bits long?

My strategy in factoring 13.3 mill exponents and up, is to save L-L testing and
DCing time by knocking some out early.  Seem to be on a roll, too,  with factors found
40% of the time, with a turnaround of 40 hours per.

Tell me I'm not just a Foole For Factores,

"Donne, Anne Donne, Undone,"
Stefanovic







_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Sat, 17 Jun 2000 13:00:57 -0700
From: Eric Hahn <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Factoring Assignments:  Are They Always "First-Time?"

Stefan Struiker wrote:
>When a requested factoring assignment is listed with, say, 52 in
>an account log, does this mean it has been factored to 52 bits,
>but  _without_ success?  Or could a factor have already been
>found in some cases, but less than 52 bits long?

If it's listed as 52 in the fact-bits column of the report, it
means that it's been trial-factored thru 2^52 without any factors
being found.  Currently, all exponents thru Prime95's limit of
79.3M have been factored to at least 2^50...  If a factor is
found for an exponent, it's eliminated from further testing
of any kind.

Eric


_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

Date: Sat, 17 Jun 2000 17:14:00 -0400
From: Jeff Woods <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Factoring Assignments:  Are They Always "First-Time?"

At 01:00 PM 6/17/00 -0700, you wrote:

>being found.  Currently, all exponents thru Prime95's limit of
>79.3M have been factored to at least 2^50...  If a factor is
>found for an exponent, it's eliminated from further testing
>of any kind.

Isn't the factor itself verified?
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ      -- http://www.tasam.com/~lrwiman/FAQ-mers

------------------------------

End of Mersenne Digest V1 #748
******************************

Reply via email to