Mersenne Digest Sunday, May 16 1999 Volume 01 : Number 558
----------------------------------------------------------------------
Date: Sat, 15 May 1999 09:56:32 +0200 (CEST)
From: Henrik Olsen <[EMAIL PROTECTED]>
Subject: RE: Mersenne: I am curious
On Fri, 14 May 1999, Chris Jefferson wrote:
> ---QUOTE---
> I was being a little sarcastic. I think that the original poster who was
> wanting to team up with other people running at least 10 machines is not in the
> spirit of the adventure. I think it is fine to make a team if everyone on the
> team has regular physical access to each machine, but I don't like the idea of
> teaming up with unknown people. That's why I said "why not make everyone a big
> team", with a little sarcasm that was probably too subtle.
> ---QUOTE---
>
> Yes, I would have to agree here. Trying to create groups to get nice big
> numbers of CPU years I do agree with, but not for the money. By the way,
> aren't we forgetting something? I hope if anyone DOES win, they will give
> a reasonable portion to the people who wrote the very highly optimised
> software to do it, and the people who made sure they weren't re-checking
> an exponent that hadn't been checked a hundred times before....
>
> Just out of interest, can I have someone demand I give them a share of the
> money / stop being in GIMPS if they really wanted to (not that I should
> think they would...)
One thing most people seems to have forgotten when it comes to talk about
the money, is that according to the common scientific discovery rules
George Woltman and Scott Kurowski will be co-discoverers of all primes
found using mprime/prime95, and the client/server setup, so should
rightfully get a big part of the money.
Either half to George and Scott, half to the "winning" team, to split it
equally between the runner(s) and the coders, or split equally between all
involved, with George and Scott getting equal shares with the people in
the team.
Personally I have a problem with the idea of forgetting to credit the
people who made it all possible, though I can understand if people think
giving up 25.000$ for a principle sounds idealistic. :)
- --
Henrik Olsen, Dawn Solutions I/S URL=http://www.iaeste.dk/~henrik/
`Can you count, Banjo?' He looked smug. `Yes, miss. On m'fingers, miss.'
`So you can count up to ...?' Susan prompted.
`Thirteen, miss,' said Banjo proudly. Terry Pratchett, Hogfather
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Date: Sat, 15 May 1999 13:42:01 +0100 (BST)
From: Chris Jefferson <[EMAIL PROTECTED]>
Subject: Mersenne: Re: Seti@home
Just one question, couldn't you install Prime95 and the Set@home
screensaver. Surely it would be worthwhile, although not quite as much
use, to Primenet? My computer tends to have no screensaver on at least 50%
of the time it isn't switched on...
- ------------------------------------
Chris Jefferson, Girton College, Cambridge, [EMAIL PROTECTED]
- ------------------------------------
I have a proof that x^n+y^n=z^n never has integer solutions for n>2.
However, it won't fit into my signature file....
- ------------------------------------
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Date: Fri, 14 May 1999 23:59:29 +0200
From: "Steinar H. Gunderson" <[EMAIL PROTECTED]>
Subject: Mersenne: Re: Convincing administrators
On Wed, May 12, 1999 at 10:49:12PM -0700, Mersenne Digest wrote:
>From: lrwiman <[EMAIL PROTECTED]>
>Subject: Mersenne: Convincing administrators
>I'm going to try to get my school to install Prime95 on
>their >100 PII's. Does anyone have experience dealing with
>large stupid beurocracies? Any pointers? Who should I try and
>talk to first?
Sorry for being late about this. I just recently had the same
problem.
Point one: Show them that it's perfectly safe. The studies
pointed to on the GIMPS homepage made my sysadmin (which you
should obviously talk to first! This is usually one person,
and much easier to talk to than going via snailmail etc.) get
a litte less sceptical. (If you can, offer to compile it
yourself. You'll probably not have to, but it will probably help
their confidence.)
Point two: Show them that it doesn't have a speed impact.
Offer yourself to install it on one or two testing machines,
and show it doesn't even have to be noticed (the `No Icon'
option is very useful here).
Point three: Offer yourself to take all the burdens. Nobody
wants to maintain a project they barely know about.
Point four (your trump ace): The $50,000 price. While most
of us are in this for fun, $50,000 is a real lot of money.
To see it from their (your school's perspective): The chance
of winning $50,000, with no extra effort. (Considering you
don't want to keep the money yourself, of course... I
recommend discussing this after you've got the permission,
discussing such things _after_ the prime has been discovered
is nothing but trouble.)
Now, if you do get permission, I can recommend making a
self-extracting EXE that you can FTP over to every machine
and just run (all machines use the same computer ID, that
won't be any problem... you might want _not_ to include
local.ini, so Prime95 can determine the CPU type and speed
itself.). I've done this at school, and it takes me 30
seconds per machine (hit Ctrl-Esc (Win95 only) at the login
prompt, choose Run..., run "c:\windows\ftp <server>", FTP
over the file, choose Run... again, run it (make it default
extract to C:\Program Files\Prime95 when you make the EXE),
Run... "C:\Program Files\Prime95\Prime95" _twice_ and when
you see it's getting the exponents, minimize and forget).
Phew! Apologies for stealing your bandwidth :-) If you're
interested, drop me a mail and I could send you an EXE for
you to install (using your own account ID, of course).
/* Steinar */
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Date: Sat, 15 May 1999 18:04:09 +0100
From: Tony Forbes <[EMAIL PROTECTED]>
Subject: Re: Mersenne: usefulness and 486's
"David M. Moore" <[EMAIL PROTECTED]> writes
>I now have this 486 machine doing the factoring that was
>being done by the P120. Generally, it is taking almost two weeks per
>exponent.
You could upgrade to a P120 very cheaply. In England the going rate for
a P120 CPU is about 20.00GBP and 1.00GBP for a suitable motherboard. In
the US I should imagine it's the same numbers in $s. People are almost
giving them away.
>Therefore, my question is even with this two week time, is the 486
>machine doing "useful work" for GIMPS, or is it merely heating up the
>CPU? I ask this because in a couple or three weeks I may have access
>to a quantity (30 to 75) of 486DX-50 machines. If these machines can
>contribute useful work to GIMPS, I will happily give them each a mouthful
>of exponents to factor :-)
It's a nice thought, but you really need cheap electricity to make it
work. I found that a typical 486DX-33 (I don't have a -50 to hand) uses
about 21 Watts, and that's without an HDD. Multiply by 75 and it could
start to get expensive, although in the winter months you would make a
saving on your heating costs.
By contrast an AMD/K6/2-400 on a basic motherboard (no sound, no video)
and no HDD draws only about 35 Watts.
- --
Tony
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Date: Sat, 15 May 1999 11:17:54 -0700
From: Steve Johnson <[EMAIL PROTECTED]>
Subject: Mersenne: Learning FFT
Some time ago someone on the list mentioned that would like to know
about FFT. I recently picked up a book that presented Fourier
Transforms (including FFT) in a very easy to understand format.
The book is called "Who is Fourier? A Mathematical Adventure". It is
written by "Transnational College of LEX" (?). The ISBN number is
0-9643504-0-8.
Although the book starts out a little simplistic, one is able to skim
the book until unfamiliar concepts are found, and then study the book in
detail from that point forward.
Steve Johnson
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Date: Sat, 15 May 1999 21:37:47 +0200 (CEST)
From: Henrik Olsen <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Getting maximum speed out of a Linux machine
On Sat, 15 May 1999 [EMAIL PROTECTED] wrote:
<snips>
> Me neither, so far as linux is concerned.
>
> I did find that ReCache "worked" in the sense of at least making things
> no worse on a wide selection of systems running Win 9x & NT. It had least
> effect on systems which had minimal physical memory, and most effect on
> systems with lots of memory & high clock rate multipliers. e.g. on my
> PII-333 system (96 MB, NT WS 4.0) on a 256K FFT a "random" start of
> Prime95 gets an iteration time somewhere between 0.190 & 0.195 - towards
> the high end if Prime95 is started automatically by means of a shortcut
> in the "Startup" folder - whereas using ReCache I get 0.188 _consistently_.
>
> If you find ReCache doesn't work for you - even on a Windoze machine -
> then I'm sorry, but you do have the option not to use it!
This really sounds like it's a result of Intel's policy of making their
chipsets as cheap as possible.
It's a well known problem that several of the widely used Intel chipsets
can't cache memory above 64MB.
What isn't so well known is that this makes a real difference on Windows,
since Windows uses memory from the high addresses first, so the first
programs to be started ends up in uncacheable memory.
This is why it's sometimes possible to see machine performance drop when
you add more memory.
I suspect the real reason why ReCache makes prime95 faster is that it uses
up all the non cacheable memory, then loads prime85 in chacheable.
This will also be the reason for the difference on Linux, since the VM
model is completely different, and Linux specifically works around some of
the stupidities of the chipsets.
- --
Henrik Olsen, Dawn Solutions I/S URL=http://www.iaeste.dk/~henrik/
`Can you count, Banjo?' He looked smug. `Yes, miss. On m'fingers, miss.'
`So you can count up to ...?' Susan prompted.
`Thirteen, miss,' said Banjo proudly. Terry Pratchett, Hogfather
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Date: Sat, 15 May 1999 13:57:10 -0700 (PDT)
From: [EMAIL PROTECTED]
Subject: Re: Mersenne: Stoopid Bureaucracies!
> > I tried at my company too (A very large Aerospace company based in
> > Washington) and my boss said that it didn't add any value to the company
> > so she couldn't approve it. I gotta find a way to show it does have
> > value...
> >
> > -Chuck
>
> If you find one...
> 1) �50,000
> 2) Lots of free publicity
Those are precisely the reasons that scared the hell out of her. Publicity
is one of those things that large companies rarely want, only because it
rarely benefits them. I can't help but to agree with her on the publicity
thing. What do the stockholders care about mersenne primes. They wanna see
more airplanes not more mersenne primes. More airplanes = more money... On
the bright side, Boe... 'er I mean the large Washington based aerospace
company I work for, is involved in some very interesting pure mathematical
research because it does benefit many of the projects they work on. My
goal is to find one of those researchers and make them a sponsor of this
project. This way it would be seen as an innovation rather than a waste of
resources.
Disclaimer: If you think anything on this page represents the opinions of
anyone but me, you're absolutely crazy. These are my opinions and mine
alone.
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Date: Sat, 15 May 1999 19:27:57 +0200
From: "Steinar H. Gunderson" <[EMAIL PROTECTED]>
Subject: Re: Mersenne: Screen saver killers?
On Fri, May 14, 1999 at 03:56:49PM -0600, Aaron Blosser wrote:
>It could be done using Win95/98 policies, if the machines logon to a domain.
It's a NetWare system. Moreover, it's at a school, and the admin is very
afraid of file sharing in any form... (This is no problem to the screensaver
thing, but will make it difficult to copy the [pq]* files easily.)
>Or, similarly, a logon script that runs a "regedit /s" and imports some .REG
>file that sets the screen-saver to the blank screen.
This could be done, I have admin privilegies, but I'm not sure if the real
admin would apprecaite it.
>The reg entry for Win95/98 screen saver is in HKCU\Control Panel\Desktop in
>the "ScreenSaveActive" value (1 or 0 for on or off).
That was what I was looking for... Now, how to incorporate that in Prime95
is another matter, especially as I don't think George would like too many
zeroed-out security codes due to people running own-compiled versions.
>What if you periodically had each machine copy it's P/Q files to some
>central location on a server.
Yes, but how? In primenet.dll? Do we have the source for that at all?
>When an exponent is checked out by your
>pseudo proxy, have it check if there's a partially worked on P file and send
>that out or something. At the very least, it'll be nice to back those up on
>occassion to prevent lost work when someone formats their drive.
How? That is the question... I guess I need to get VC++ back, enter Windows
(yuck) and do something smart (an FTP upload, for instance). If any coders
out there are willing to help me, it would be nice.
/* Steinar */
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Date: Sat, 15 May 1999 19:57:04 +0200
From: "Steinar H. Gunderson" <[EMAIL PROTECTED]>
Subject: Mersenne: Re: Mersenne Digest V1 #557
On Sat, May 15, 1999 at 12:52:56AM -0700, Mersenne Digest wrote:
>Why not just write a piece of code that (during installation of Prime95)
>removes the screensaver start-up line in the ini (windows) files.
Well, as Prime95 is only installed once, and the users are adding screen
savers all the time, this will help little.
- --- snip ---
>My solution was to put a different copy of Prime95 on the home
>directory of each workstation on the server they connect to.
On our system, each workstation doesn't have their own home
directory, and there's nothing I can do about it :-(
>Of course it does waste about 4 MB of disk space for each
>workstation * 275 workstations = 1.1 GB which is nothing in server
>space these days.
Well, considering that our server is only a bit over 10 GB, and we're
already hard pushed ;-)
- --- snip ---
>I now have this 486 machine doing the factoring that was
>being done by the P120. Generally, it is taking almost two weeks per
>exponent.
The machines at school are estimated to use about three months each
(not 24/7) :-) Just have patience.
>Therefore, my question is even with this two week time, is the 486
>machine doing "useful work" for GIMPS, or is it merely heating up the
>CPU? I ask this because in a couple or three weeks I may have access
>to a quantity (30 to 75) of 486DX-50 machines. If these machines can
>contribute useful work to GIMPS, I will happily give them each a mouthful
>of exponents to factor :-)
I asked George about this once. His answer (not 100% accurate, but the
wording was similiar): `Every little bit helps!' Yes, they will be doing
useful work.
- --- snip ---
>On a related note, I've found that for LL testing, the speed of a
>Pentium MMX and a Pentium II is about the same adjusted for clock speed,
>but for factoring, the P-II seems to finish in about half the time.
Curious -- I'm just now talking to George about improving the LL code
for P6 (PPro/PII/PIII). Some volunteer already improved the factoring
code. Look at the whatsnew.txt file from Prime95:
===
New features in Version 14.3 of prime95.exe
- -------------------------------------------
1) The Pentium Pro factoring code is nearly twice as fast compared
to version 14.2.
===
In fact, 486 code is often better for P6 than Pentium code. If you don't
believe me, look at what GNU did for glibc2 (the now-standard Linux C
library): In the bottom, you have C code. In addition, there are some
special 386-optimized routines. The 486 `inherits' these routines, and
adds some more 486-specific ones. Pentium inherits the 386 and 486
routines. BUT... Pentium Pro inherits _only_ 386 and 486 code, not
Pentium code. (Trying to pipeline FPU-code the same way for P6 as for
Pentium is generally not helping, since the P6 does out-of-order
execution already. Therefore, all the FXCHs are not useful, and just
eating up time.)
The problem is that I don't have access to masm :-( George has promised
to look into PII optimization for v19.
>This indicates to me that there's room for more improvement, though how
>that would work in details isn't clear, since I couldn't find the source
>for the factoring part of the program when I looked.
It's in factor64.asm (at least part of it).
- ---
>I'm not in favour of "forcing" this solution on to users, it sounds a
>bit draconian to me. Also, I've been known to criticise vehemently
>software vendors whose setup programs trample on users' personalizations.
The problem is that our `users' (pupils) generally know nothing about
PCs, most of them can barely surf the web. Trying to explain to them
that a maths program (there are not many of us knowing that Prime95
is running anyway, I've used `No Icon' so people won't tamper with it)
doesn't like screen savers will not be very constructive.
>I would much prefer a programme of user education - either convince them
>that animated screensavers are a waste of resources which could be used
>more profitably, or at least get them to change the priority of Prime95
>to 4 so that it's guaranteed a reasonable chance of getting CPU cycles.
For `normal' users, yes. For those, sorry, no :-)
>BTW experiments indicate that screensavers usually don't consume more than
>25% of the available CPU cycles anyway. I'd rather have a user who feels
>they really need their animated screensaver run Prime95 at 75% of its
>potential than not run Prime95 at all.
What about letting users keep their screen savers all day, and just reset
them the first time they're rebooted in the morning?
- --- snip ---
>Perhaps because the LL test is critical on the FPU speed, whereas the
>factoring code is critical on the integer part of the CPU, in particular
>the efficiency of the (I)MUL instruction.
There are two factoring versions: FPU (for Pentium/P6) and integer (all
others).
>This would appear to adequately explain the performance difference
>between P5 and P6, and also give an explanation as to why the 486 is
>apparently so much less efficient even after correction for clock
>speed.
P6 is a totally different concept that P5 in general. P6 is actually
a RISC processor. A decoder unit converts x86 CISC instructions to
what Intel refers to as `micro-ops'. The Pentium II/Pro can schedule up
to five micro-ops per cycle, but a much more typical rate is three
micro-ops per cycle. (This data is loosely based on Intel documents.)
Clearly, the intent must be using as few micro-ops as possible to
do a given task, AND making sure the decoder can provide enough micro-
ops to the computation core (this is done by placing more complex/
less complex instructions in a special pattern). (Again based on
Intel info.)
The differences spring from that the cycle count on P5 is not always
the same as the micro-op count on the P6. To take a very typical
example:
FADD QWORD PTR mem (mem is a memory reference)
FXCH ST(1)
FADD QWORD PTR mem (mem is the same memory reference)
FXCH ST(1)
On the P5, this will take only two cycles to complete. The FADD is scheduled
in the U-pipe (correct me if I'm wrong... perhaps the U-pipe is an integer-
only pipe), and the FXCH is scheduled in the V-pipe. However, on the P6,
this is sub-optimal code. The FADD translates into two micro-ops (one to
load `mem' into memory, and one to do the add), and the FXCH translates
into one. Consequently, this will take 6 micro-ops to execute. However,
FLD mem
FADD ST(1),ST
FADDP ST(2),ST
will do exactly the same (I hope...), and just take three micro-ops. One
cycle saved.
Sorry for bothering you all -- when I first start to write, I can't stop.
- --- snip ---
>It might be worth trying at the end of the
>first pass then exiting ReCache immediately, or at the end of the
>first pass & starting the second pass - you could then abort the
>second pass at the halfway mark, the idea being that ReCache should
>continue thrashing long enough for Prime95/mprime to get itself
>initialized as far as allocating its work vectors.
I'll try... But why should ReCache still be thrashing when Prime95 boots
up?
>I did find that ReCache "worked" in the sense of at least making things
>no worse on a wide selection of systems running Win 9x & NT.
Yes, it makes things more `stable', as one user pointed out.
>If you find ReCache doesn't work for you - even on a Windoze machine -
>then I'm sorry, but you do have the option not to use it!
Hmmmm, good thing -- I don't always have that option :-(
/* Steinar */
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Date: Sat, 15 May 1999 14:46:59 -0700 (PDT)
From: [EMAIL PROTECTED]
Subject: Re: Mersenne: SETI on ABC News last night
> Would anyone care to comment on the appeal of SETI? Personally speaking, it
> doesn't interest me at all. I don't consider its goals to be terribly useful
> or important, and I don't think that it has a reasonable chance of
> accomplishing anything. But as number theory enthusiast I find something
> intrinsically interesting and worthwhile about finding factors and searching
> for Mersenne primes. I am probably in a minority of the general population
> in this regard.
Yes, I have a comment. As was said in the movie Contact, "[if there aren't
any intelligent civilations out there] it sure would be a waste of space".
If you look at it, the search for Mersenne primes is intrinsically same as
the search for extraterrestrial life. No one can say for sure if there
really are any more Mersenne primes to be found. We still look for them
though, because the statistical likelihood of finding one is pretty
compelling. Given the vast amount of space out there and the incredible
number of galaxies (most of which we do not know about) I would say the
likelihood is equally as strong, if not stronger that something
intelligent is out there. It is a highly subjective argument whether it is
worthy to find them or not, however you cannot deny the likelihood of them
being out there. One could argue that if we cannot even get along with
each other, why should we try to integrate another paradigm into our
culture. Personally, I am of the belief that everytime you raise the bar,
the issues and problems you once had, suddenly look insignificant.
Remember how hard multiplication was when you were in 1st grade? Did you
REALLY have it mastered by the time you got into long division? I bet you
have it mastered now, because you kept on raising the bar. In my travels,
I have never mastered anything by focusing on it like a laser. Instead, I
mastered it over time by looking at it from many perspectives. Lets just
imagine for a moment that we have made contact with a new culture and we
are able to transfer knowledge between us. Do you REALLY think that they
have developed along the same lines we have? Of course not. They might
think some of our problems are trivial, "Oh, 2^N-1??? Yes, that is part of
our basic math studies, we solved that problem like this and here are some
of our basic corollaries.". Other things might amaze them, "Wow, you
managed to tie together hundreds of different language systems, with this
UNICODE thing?". In this sense, the legitimacy of the SETI project is
based not on what we know we will find, but what we don't know that we
might find.
One other thing is that the concept of distributed computing (much like
the open source movement) is just starting to gain momentum because of
real world proof. We can't possibly believe that our project alone could
do that. Mersenne primes captured our hearts and minds, however other
people don't feel the same. Perhaps BOVINE is more interesting to them, or
maybe SETI, Golumb Rulers or PI is more interesting than GIMPS. Look at
the big picture, who says any project is more worthy than another. All of
the projects I have seen so far have advanced human knowledge more than
has ever been possible. I understand the fear that we'll lose momentum.
However I'd like to take George Woltman's lead on this one and embrace the
other projects. Not because we will lose members to these other projects,
but because the other projects will advance the science of distributed
computing, which in my humble opinion, will help us much more in the long
run.
Thanks for your time. And yes, I will continue to contribute my meager
CPU cycles to GIMPS.
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Date: Sat, 15 May 1999 17:41:20 -0400
From: George Woltman <[EMAIL PROTECTED]>
Subject: RE: Mersenne: usefulness and 486's
Hi,
At 01:05 AM 5/15/99 -0500, David M. Moore wrote:
>> You could also do something more conducive to the 486 environment...I
>> don't know - is ECM good work for a 486?
>
>I don't know. That was going to be my next question if it was decided
>that 486's are wasting time :-) Although none of the other projects have
>really grabbed my attention, I would put the 486's on to another project if
>they were more suited to what ever that project does.
If you are willing to spend the money on the electricity, then the "best"
project will be one that does integer work rather than floating point work.
The 486 FPU is 4 to 5 times slower than a Pentium FPU, but only twice
as slow on integer operations (after adjusting for MHz differences).
Prime95 (LL, ECM, and factoring), Proth, and I suspect SETI are mostly
floating point. Conrad Curry's NFS program, ECM-NET, and the encryption
cracking are probably mostly integer operations.
Of course, you have to weigh that against which projects you find
most worthwhile and fun.
Regards,
George
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Date: Sun, 16 May 1999 00:04:46 -0500
From: [EMAIL PROTECTED]
Subject: Mersenne: old XT's crunching numbers?
Has anyone had any luck making the prime number software run on clumky
286 PC's? or maybe even on old XT's (with about 1024 of RAM). I'm not
even sure if the software exists for XT's...
Is there a way of finding out how many computers are linked up to the
GIMPS mainframe and if so, can one also see what the progress is
(collectively)? I suppose i'm really asking for the mainframe's web page.
Thank you all for your time
- -oliver
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Date: Sat, 15 May 1999 21:42:21 -0400 (EDT)
From: "Vincent J. Mooney Jr." <[EMAIL PROTECTED]>
Subject: Mersenne: Little Numbers
I wonder who has the best little number and what configuration is used.
Iterations .203 or .189 or what? Perhaps someone can decide what is a good
current PC for the users on Mersenne.
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Date: Sun, 16 May 1999 00:01:56 -0600
From: "Aaron Blosser" <[EMAIL PROTECTED]>
Subject: RE: Mersenne: Screen saver killers?
> From: Steinar H. Gunderson
> Subject: Re: Mersenne: Screen saver killers?
> On Fri, May 14, 1999 at 03:56:49PM -0600, Aaron Blosser wrote:
> >It could be done using Win95/98 policies, if the machines logon
> to a domain.
>
> It's a NetWare system. Moreover, it's at a school, and the admin is very
> afraid of file sharing in any form... (This is no problem to the
> screensaver
> thing, but will make it difficult to copy the [pq]* files easily.)
Well, you could easily implement a Win95 policy on a Netware system. I'm a
bit unfamiliar with Netware, but here's a quick cut and paste of where to
put the file:
- --------------
To set up for automatic downloading on NetWare networks
1. In the Network option in Control Panel, make sure that Microsoft Client
for NetWare Networks is specified as the Primary Network Logon client, and
that a preferred server is specified in properties for the network client.
For more information, see Chapter 9, �Windows 95 on NetWare Networks.�
2. Create the policy file to be downloaded and save it in the following
location:
\\preferred server\sys\public\config.pol
For NetWare networks, the client computers must be running Microsoft Client
for NetWare Networks. If the client computers are using NETX or VLM, then
policies must be downloaded manually.
Important Make sure you place system policy files on the user�s preferred
server. Policy files are not available if they are stored on other NetWare
servers or on computers running File and Printer Sharing for NetWare
Networks.
- ----------
Hope that's helpful.
> >Or, similarly, a logon script that runs a "regedit /s" and
> imports some .REG
> >file that sets the screen-saver to the blank screen.
>
> This could be done, I have admin privilegies, but I'm not sure if the real
> admin would apprecaite it.
Oohhh...well, make sure he's on your side before doing this I guess.
> >What if you periodically had each machine copy it's P/Q files to some
> >central location on a server.
>
> Yes, but how? In primenet.dll? Do we have the source for that at all?
If it were me, I'd setup some scheduled job on each machine to periodically
copy the files to the server.
With Windows NT, it's even easier because instead of having each machine
copy the file to some share, you can remotely connect to each machine and
pull the files off. I suppose you could do that with Win95/98 if each
machine had a share pointing to the location of the files...
> How? That is the question... I guess I need to get VC++ back,
> enter Windows
> (yuck) and do something smart (an FTP upload, for instance). If any coders
> out there are willing to help me, it would be nice.
My motto is, if it can be done with normal batch commands, or using a few
3rd party tools, why waste time coding it? But then again, I'm so rusty
with C++ that it'd take me that much more time anyway.
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Date: Sun, 16 May 1999 00:14:18 -0600
From: "Aaron Blosser" <[EMAIL PROTECTED]>
Subject: RE: Mersenne: SETI on ABC News last night
> Yes, I have a comment. As was said in the movie Contact, "[if there aren't
> any intelligent civilations out there] it sure would be a waste of space".
> If you look at it, the search for Mersenne primes is intrinsically same as
> the search for extraterrestrial life. No one can say for sure if there
> really are any more Mersenne primes to be found. We still look for them
> though, because the statistical likelihood of finding one is pretty
> compelling. Given the vast amount of space out there and the incredible
> number of galaxies (most of which we do not know about) I would say the
> likelihood is equally as strong, if not stronger that something
> intelligent is out there.
I find the odds overwhelmingly depressing. If we say the universe is 20
billion years old or so, and it took several billion for even the first
stars to form, and another several billion for the planets and common
elements to congregate, and then another several billion years for planets
to cool, etc.
Then the odds of having planets suitable for life, such as earth. I'm
certain there are only thousands of such planets out of possible billions.
Then, whether you believe in evolution or not, there are still pretty big
odds against life forming anyway, but I'll gloss over that and say it
happens but it's rare (something I don't agree with anyway). And then,
there are the odds against any such life evolving into a form intelligent
enough to become intelligent enough to develop transmission mechanisms.
And then, barring any fictional FTL messaging, there is the incredible
amount of time it would take for any signals to even reach our isolated
planet, on a distant spiral arm of a remote galaxy. And any signals would
be incredibly weak if they even did exist, and would be barely detectable,
if at all, against the background radiation of space (big bang radiation).
And the fact that there is just SO much area to cover, so many signals to
analyze.
And then the fact that we've only been scanning space for any kind of
signals for only a few decades.
It's like looking for a needle (that might not exist) in one of trillions of
haystacks, and expecting to find that needle in the first few tries.
Naturally, I'd be blown out of my socks if we found any sort of pattern
emanating from deep space, indicative of intelligence (or signs of
intelligence from Earth itself :-), but I feel quite confident in saying
that the odds are 100% in favor of us never finding any such signs before
Sol blinks out for good.
Mersenne Primes on the other hand (ob. reference) are much more likely (and
expected) to be found, probably this year sometime I'd hazard to guess.
I'll stick with GIMPS. :-)
Aaron
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Date: Sun, 16 May 1999 08:52:12 +0200 (CEST)
From: Henrik Olsen <[EMAIL PROTECTED]>
Subject: RE: Mersenne: Screen saver killers?
On Sun, 16 May 1999, Aaron Blosser wrote:
> To set up for automatic downloading on NetWare networks
> 1. In the Network option in Control Panel, make sure that Microsoft Client
> for NetWare Networks is specified as the Primary Network Logon client, and
> that a preferred server is specified in properties for the network client.
> For more information, see Chapter 9, �Windows 95 on NetWare Networks.�
> 2. Create the policy file to be downloaded and save it in the following
> location:
>
> \\preferred server\sys\public\config.pol
>
>
> For NetWare networks, the client computers must be running Microsoft Client
> for NetWare Networks. If the client computers are using NETX or VLM, then
> policies must be downloaded manually.
Slight bit of FUD there, Netware's own Client32 works just as well.
> Important Make sure you place system policy files on the user's preferred
> server. Policy files are not available if they are stored on other NetWare
> servers or on computers running File and Printer Sharing for NetWare
> Networks.
>
> Hope that's helpful.
- --
Henrik Olsen, Dawn Solutions I/S URL=http://www.iaeste.dk/~henrik/
`Can you count, Banjo?' He looked smug. `Yes, miss. On m'fingers, miss.'
`So you can count up to ...?' Susan prompted.
`Thirteen, miss,' said Banjo proudly. Terry Pratchett, Hogfather
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Date: Sun, 16 May 1999 08:55:32 +0200
From: Petri Holopainen <[EMAIL PROTECTED]>
Subject: Re: Mersenne: SETI on ABC News last night
Aaron Blosser wrote:
>
>
> <...snip...>
>
> Then the odds of having planets suitable for life, such as earth. I'm
> certain there are only thousands of such planets out of possible billions.
> Then, whether you believe in evolution or not, there are still pretty big
> odds against life forming anyway, but I'll gloss over that and say it
> happens but it's rare (something I don't agree with anyway). And then,
> there are the odds against any such life evolving into a form intelligent
> enough to become intelligent enough to develop transmission mechanisms.
>
This is all true, I guess, but it only takes *one* old civilization
to populate the whole galaxy, given enough time. Since the Milky Way
is as old as it is, I'd say the propability of at least one
interstellar civilization in our Galaxy seems pretty good.
>
> I'll stick with GIMPS. :-)
Me too, but I've also joined SETI@home. I guess I can share my cycles
between these two great projects.
- -- Petri H.
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Date: Sun, 16 May 1999 10:08:01 -0000
From: [EMAIL PROTECTED]
Subject: Re: Mersenne: Getting maximum speed out of a Linux machine
>> If you find ReCache doesn't work for you - even on a Windoze machine -
>> then I'm sorry, but you do have the option not to use it!
>
>This really sounds like it's a result of Intel's policy of making their
>chipsets as cheap as possible.
>It's a well known problem that several of the widely used Intel chipsets
>can't cache memory above 64MB.
True - but the example I cited uses the LX chipset (Intel AL440LX board),
which definitely caches more than 64 MB memory. Or, at least, the system
speed stayed the same when I upgraded from 64 MB to 96 MB.
My other home system - dual PII-350 on a Supermicro P6DBS, BX chipset,
128 MB memory - also shows a big response to ReCache. My work system -
Celeron 266, EX chipset on "unknown" M/B, only 32 MB memory - shows
little response. In fact ReCache's name comes from the fact that
originally I thought of clearing crud out of the L2 cache. I realize
now that this is probably incorrect, but the project name stuck 'coz
I couldn't be bothered to change it ...
>What isn't so well known is that this makes a real difference on Windows,
>since Windows uses memory from the high addresses first, so the first
>programs to be started ends up in uncacheable memory.
>This is why it's sometimes possible to see machine performance drop when
>you add more memory.
With Win 9x, yes. I believe NT tends to allocate from the bottom up.
>I suspect the real reason why ReCache makes prime95 faster is that it uses
>up all the non cacheable memory, then loads prime85 in chacheable.
Are you _sure_ this is the case - most of my development was done under NT
but I did check the effects were similar under 9x - also I thought that
deficient chipsets, like TX, failed to cache _any_ memory once you went
over the 64MB cacheable memory limit?
>
>This will also be the reason for the difference on Linux, since the VM
>model is completely different, and Linux specifically works around some of
>the stupidities of the chipsets..
But I've never seen a case of a system which will run mprime over linux
significantly (>1%) faster than it will run Prime95 over Win NT - except
for one pathological case where memory was insufficient to run _anything_
properly over NT - when the systems were otherwise idle.
This last comment was _not_ intended to start, or provide ammunition for
any existing, OS war - I'm just trying to make the point that Windoze is
not neccessarily a total disaster from the performance point of view -
I actually _prefer_ linux but find myself forced to keep some systems
running Windoze in order to maintain collaboration with fellow workers
who insist on using M*cr*s*ft applications.
Regards
Brian Beesley
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End of Mersenne Digest V1 #558
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