Re: Mersenne: idea for a new prime95 version

2001-02-04 Thread Luke Welsh

At 01:50 AM 2/4/01 -0600, Steve wrote:
There are so many screensavers available now that one can be found to match
any personality,

Why not identify a couple of existing screensavers that could be
"compatible" with Prime95 and then approach the author(s). ask
them to make a verion that includes George's stuff?

--Luke

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Re: Mersenne: Re: Mersenne Digest V1 #812

2001-02-04 Thread Brian J. Beesley

On 3 Feb 2001, at 23:16, Stephan T. Lavavej wrote:

 What about some of the new gaming platforms. I think some have computing
 capabilities equivalent to P133s and they have modem hookups. However, I'm
  not sure how feasible/worthwhile it would be to write progamrs to do this.

P133 isn't much by modern standards.
 
 Better yet, the Xbox.  It will actually have a PIII-733 inside it, AND a
 hard drive, and a built-in broadband connection.  All that would be required
 is the ability to run arbitrary code from the hard drive, and poof, you have
 something like a million potential boxes on which to run Prime95.

Assuming, of course, that PIII-733s are still available when the Xbox 
goes into mass production. Intel's production strategies might force 
use of a more powerful processor :)

I guess it will be running something that is recognisably Windows 
"under the hood", as well. In which case, the programming overhead 
might be _very_ small.

I also guess that there _will_ be some means of running third-party 
code ... people are going to want to do things that Microsoft haven't 
thought of ... the free market system usually manages to rectify 
these sorts of deficiencies!

Furthermore, I'd guess that Bill Gates would be rather distressed to 
hear your estimate of only one million sales. He probably hopes unit 
sales will run into eight figures.

Regards
Brian Beesley


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Re: Mersenne: idea for a new prime95 version, QA, primenet etc

2001-02-04 Thread Brian J. Beesley

On 3 Feb 2001, at 17:03, Jeff Woods wrote:

  With increasing exponent size (and therefore run time), I'd like to
  see PrimeNet evolve to track intermediate residues  also to be able
  to coordinate parallel LL testing  double-checking, so that runs
  which are going wrong can be stopped for investigation without having
  to be run through to the end.

 I think this is an EXCELLENT idea, but remember that the "s" values (i.e. 
 the intermediate residue/modulus) for such numbers is quite simply 
 enormous.   One couldn't (and shouldn't) check the entire intermediate 
 value, but merely the last "x" bits, where "x" is enough to be reasonably 
 certain that a match isn't random chance -- say, the final 1024 bits.

64 bits is enough to be pretty confident! We need a recovery 
procedure anyway, to cope with any systematic bugs which may exist.
 
 PrimeNet would thus also have to carefully assign the exponents to similar 
 machines with similar runtimes and performance, as it would do little good 
 to assign the primary test to an Athlon-800 and the "real-time" 
 double-check to a much slower machine, as the Athlon would quickly outpace 
 the second check.
 
 If a discrepancy was found in a real-time double-check, a ternary run on a 
 different machine could determine which (if either) of the two intermediate 
 residuals was correct, and the tests could proceed from there, with both 
 original machines assuming the same correct residue.
 
My reply to Ken Kriesel's message on this topic shows how the need 
for paired systems to be evenly matched could be avoided - though it 
is certainly preferable that gross mismatches are avoided. However, 
there shouldn't be much problem providing reasonable matches, since 
the PrimeNet server knows each participating system's CPU type  
clock speed.

 Also, if this did evolve, I'd suggest that the "double-checker" be given 
 equal credit with the primary machine, for purposes of credit in history 
 books as discoverers, and/or EFF monies.

This question obviously needs to be addressed, if only to keep 
lawyers out of our hair. I agree with Jeff on this one.
 
 Note that there's a point of futility, at which a "tie-breaker" ought to 
 merely be a triple-check, run to conclusion.  Let's say on a 14-month co-op 
 effort, 13.6 months into it a discrepancy was found.   Both machines ought 
 to finish, and just have it triple-checked, rather than suspending both, 
 awaiting a tiebreaker.   While I'm sure someone could solve for the optimum 
 cutoff point where tiebreakers are not useful, my guess would be that it is 
 around 85% of the way to completion.

With the suggestions in my reply to Ken, having "late" checkpoints 
doesn't do much to slow down completion - the leading system proceeds 
unless or until the trailing system finds a discrepancy. However, I 
certainly agree that there's not much point in having a checkpoint at 
iteration 14 million if you're testing e.g. exponent 1403. I'd 
suggest "missing out" the last checkpoint if the number of iterations 
remaining at that point is less than half the iterations between 
checkpoints.

Regards
Brian Beesley

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Re: Mersenne: idea for a new prime95 version

2001-02-04 Thread Brian J. Beesley

On 4 Feb 2001, at 1:50, Steve wrote:

 "Alexander Kruppa" wrote:
 
 The screen-saver idea is important for another reason.
 I asked several coworkers and secretaries to let Prime95 (NTprime,
 actually) run on their PCs and they agreed, but they were less than
 happy when I asked them to change the pretty 3-d screen savers for
 something that lets NTprime have more cpu power. With the selection
 Microsoft offers right now, that means "Blank Screen" or "Marquee" -
 neither is extremely exciting to watch. Before long, most of them went
 back to the old screen savers and NTprime slowed down to a halt.
 
 
 "...slowed down to a halt" is no exaggeration. I've seen screensavers slow
 it down to more than 7 seconds per iteration at 800+ MHz. I have it running
 on some PCs where the user has the screensaver set to start after 5 minutes
 then sets the power management so the monitor turns off after 10 or 15
 minutes... and what really bothers me is that the screensaver continues to
 run even with the monitor off. (Is there some way to prevent that which I
 don't know about?)

Not that I'm aware of, either. You're supposed to use ACPI to make 
the processor sleep rather than worry about details such as whether 
the screensaver is still running with no visible display.

 One idiot even had her settings such that the screensaver
 didn't start until _after_ the monitor went off.

No accounting for stupidity! I wonder if you could get away with 
tricking users like this into staring at the "blank screen" saver for 
hours on end by fooling them that, very occasionally, something 
"interesting" happens? ;-
 
 There are so many screensavers available now that one can be found to match
 any personality, and I have found it impossible to get people to let go of
 one they really like. So I don't believe Brian's idea will do very much
 good; but then every little bit helps.

Could I respectfully point out that the windoze screensavers run at 
priority 4. If you raise Prime95/NTPrime's priority to 4, you will 
split CPU time more or less evenly between the screensaver and the 
Mersenne client. In fact there should be a bit more going our way 
than the screensaver does; the screensaver does voluntarily 
relinquish the CPU occasionally - otherwise a client running at 
priority 1 would get nothing. 

On the principle that half a system is better than nothing, this 
trick is probably worth publicising, if it will let users keep their 
favourite screensaver running.

I'd warn strongly against raising the priority of Prime95/NTPrime any 
higher than 4, as there could be serious consequences to the 
performance of foreground tasks.

BTW, and getting way off topic, on windoze I use a freeware gadget 
called Sleeper which I downloaded from the net ages ago. Still works 
on Win2K though. This has "hot spots" in two corners of the screen 
(configurable in size and which two corners are used); if you park 
the mouse pointer in one of the "hot spots", the screensaver 
activates "immediately" (actually there is a 2 sec delay) whilst 
parking the mouse pointer in the other "hot spot" prevents the 
screensaver from ever activating. If the mouse pointer is elsewhere, 
the screensaver activation is normal (as if Sleeper were not 
present).

I use this (in conjunction with the screensaver password feature, and 
the standard "blank" screen saver) as a security tool, to lock access 
to my system through the console when I'm temporarily absent e.g. 
gone for a leg stretch. Obviously you need to set the BIOS boot  
setup passwords as well, to prevent people from breaking in by simply 
resetting the system. And, no, it isn't perfect, but then no security 
system is.

The "never activate" feature is also useful, as it prevents 
screensaver activation from interfering with tasks like scandisk and 
defrag which don't take kindly to anything happening which causes the 
volume being processed to be accessed.

Sleeper is tiny and has no detectable processing time overhead. 
Obviously it does need to steal a few cycles, but it really isn't 
significant, even on a slow system.

Regards
Brian Beesley

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Re: Mersenne: idea for a new prime95 version

2001-02-04 Thread Marcel van de Vusse

Steve wrote:

 "...slowed down to a halt" is no exaggeration. I've seen screensavers slow
 it down to more than 7 seconds per iteration at 800+ MHz. I have it running
 on some PCs where the user has the screensaver set to start after 5 minutes
 then sets the power management so the monitor turns off after 10 or 15
 minutes... and what really bothers me is that the screensaver continues to
 run even with the monitor off. (Is there some way to prevent that which I
 don't know about?) One idiot even had her settings such that the screensaver

I have to agree here. I installed Prime95 on my parent's computer, and
took it off again after I found out the screen saver keeps going after
windows turns the monitor off (3D flowerbox or something like that).

I guess I overestimated microsoft's intelligence when I actually
expected the screen saver to quit after the monitor was blanked (end
eventually turned off).

Is there any way somebody could modyfy this behavious?

Marcel
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Re: Mersenne: idea for a new prime95 version

2001-02-04 Thread Alexander Kruppa

"Brian J. Beesley" wrote:
 
 On 4 Feb 2001, at 0:27, Alexander Kruppa wrote:
 
 Well, you could bump NTprime's priority to 4; that would let NTprime
 steal CPU cycles off the screensaver, without being too obvious to
 the user :) Don't go any higher, as you would risk seriously
 impacting the performance of foreground tasks.

One big point you can use to convince coworkers/managers etc is that
Prime95 only uses cpu time that no other process wants. Most everyone I
asked wanted explicit confirmation that Prime95 does not take cpu time
while other processes are running. I can just see them frowning at me
when I say that Prime95 will now steal only such a little amount of cpu
time..
No, I think Prime95 really should run at idle priority.

  With the selection
  Microsoft offers right now, that means "Blank Screen" or "Marquee" -
  neither is extremely exciting to watch. Before long, most of them went
  back to the old screen savers and NTprime slowed down to a halt.
 
 Does that mean that the primary purpose of the computers used by your
 coworkers is to provide a colourful distraction?

Putting a picture on a wall in an office is not the primary purpose of
an office either, yet most everyone I know does it. Everyone can set up
his workplace the way he wants it.
I can't go and tell them what to do with their computers, I was happy
enough when they agreed to let me install a strange piece of software.
If they like colorful displays then why shouldn't they have them? The
solution would be to write a screen saver that is pleasing to look at
(and not just for tech dweebs) and yet leaves enough cpu time for an
idle-priority background process.

 I suppose you could try fibbing that something interesting happens
 occasionally in the blank screen (like the teapot in the 3D pipes
 saver), and see how long you can make them stare at it ;-
 
 Regards
 Brian Beesley

How about a cute kitten that sleeps for hours, wakes up, stretches,
walks to another corner of the screen and sleeps some more? 99% static
graphics, has the "oh sweet!!" bonus and people will try to leave the
computer alone as not to disturb the kitten while Prime95 happily
crunshes away :)

Ciao,
  Alex.
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Mersenne: Statistics

2001-02-04 Thread Martijn

Hi

I think the overall statistics updated ~ daily makes seti and distributed.net
"sexier" than primenet. When hooking up that brand new 1.2 GHz machine, you have
the first results in 1-2 days, (Score wise) I think it might help to award
primenet points at every progress report.

The score can be sorted on total score for finished work + a Work In Progress
(WIP)score (1 partial score / computer ID) That way people will get faster
statistic results
which actually is important to a lot of people. When a computer reports the final
result the WIP can be reset to 0 and the finished work score can be increase with
the points for the finished exponent (as now). The comptational overhead can be
kept low if only one top list is made a day (this is the same frequency as
distributed.net and probably also the same as the seti statistics charts.)

Kind Regards, Martijn



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[Fwd: Re: Mersenne: Distributed Computing Mandatory For Juno's Free Users]

2001-02-04 Thread Halliday, Ian

From Nathan, for the list

From: Nathan Russell [EMAIL PROTECTED]
References: [EMAIL PROTECTED]

Halliday, Ian wrote:

 http://au.dailynews.yahoo.com/headlines/20010203/nbtech/981156900-2685255736.html
 describes new conditions for free juno users - once again SETI is cited
 as a "successful" example of distributed computing. IIRC, we have had
 four successes, they haven't had any...

Yes, we have.  If GIMPS succeeds yet again, the finder of the prime will 
get money, and fame within the mathematical community.  Ditto if a user 
of the distributed.net project finds a RC5 key (except less money and 
more transitory fame).  It could be argued that someone who finds /them/ 
with SETI and is announced as a co-discoverer will not be wanting for 
fame or money for the rest of his/her life.  Additionally, SETI is as 
likely to make a discovery now as it ever was (read: not very).  d.net 
and GIMPS are both attempting tasks which are orders of magnitude less 
likely to succeed than those they have completed in the past. 

As another point, I know many who are in SETI solely for the nice 
graphical display.  I don't know whether GIMPS, given the abstract 
nature of the work we do, could ever really develop such a display. 

 
 How will the new conditions described in their terms affect us (or any
 other voluntary distributed project for that matter) ?

I sincerely doubt that many Juno users will stick with that service if 
Juno ever attempts to fully enforce the terms:

"[users permit Juno to] upload such results to Juno's central computers 
during a subsequent connection, whether initiated by you in the course 
of using the Service or by the Computational Software."

(snip)  "Juno may require you to leave your computer turned on at all 
times, and may replace the 'screen saver' software that runs on your 
computer while the computer is turned on but you are not using it. "

Does that mean that Juno will become angry at subscribers who take their 
machines down for maintence, or do a reboot mandated by the operating 
system? 

My ex-girlfriend from high school and her family use Juno as their free 
email provider.  I sincerely doubt that, if Juno began enforcing these 
sorts of terms, they would switch to e.g. NetZero or another adware 
internet provider, and begin using web-based email. 

The privacy concerns alone of Juno running software quasi-voluntary on 
customer systems are chilling.  I just checked Slashdot, but they've had 
something up since yesterday:

http://slashdot.org/article.pl?sid=01/02/01/2127239mode=nested


 
 
 On a different matter, what happened to Lennart's offer of champagne to
 the person who guessed a milestone date correctly? Have we reached that
 milestone yet? If so, who won?
 
 Regards,
 
 Ian

Nathan Russell
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Mersenne: Re: idea for a new prime95 version

2001-02-04 Thread Joshua Zelinsky



Could I respectfully point out that the windoze screensavers run at
priority 4. If you raise Prime95/NTPrime's priority to 4, you will
split CPU time more or less evenly between the screensaver and the
Mersenne client. In fact there should be a bit more going our way
than the screensaver does; the screensaver does voluntarily
relinquish the CPU occasionally - otherwise a client running at
priority 1 would get nothing.

It would be really useful if this was in the readme file _ FAQ list.

Regards,

Joshua Zelinsky
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Re: Mersenne: idea for a new prime95 version, QA, primenet etc

2001-02-04 Thread Lars Lindley

  Nothing built by human hands is perfect, so, sure, the program could
  be improved! Personally I'd like to see an optimization for Athlon;
  at the expense of having to load different versions for different
  processor types, I'd like to see seperate "streamlined" versions of
  the code optimized for different processor types rather than one
  monolithic program with everything embedded in it; 

Optimizations for Athlon would be very welcome :)

Using a modularized version of the program (sort of like dll's) would keep 
the simlicity in using the program AND keep it resource-efficient.

The added download time shouldn't be a problem since it is a one-time 
download and for example SETI@Home requires daily downloads on a fast machine.
(That project isn't going all to bad :))

just my two cents...

/Lars
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Re: Mersenne: Re: screensavers

2001-02-04 Thread Steve

Could I respectfully point out that the windoze screensavers run at
priority 4. If you raise Prime95/NTPrime's priority to 4, you will
split CPU time more or less evenly between the screensaver and the
Mersenne client. In fact there should be a bit more going our way
than the screensaver does; the screensaver does voluntarily
relinquish the CPU occasionally - otherwise a client running at
priority 1 would get nothing.


A while back I set the priority for Prime95 to 5 at night and left it at 1
during the day on several PCs. In some cases in helped tremendously but in
other cases it had no effect whatsoever. I don't remember if that correlated
with machine type, OS or screensaver type; it was quite some time ago. I may
revisit that and look for a pattern. I do remember one in particular, the
"win95" screensaver running on a pentium pro with Win95 OS brought Prime95
almost to a dead stop, but changing the priorities at night slowed the
screensaver so much you could barely see it move while Prime95 ran almost at
optimum speed. I remember that one because it was the most successful
implementation of the resetting of priorities. Others ranged from some
effect to no effect. I believe the least successful were some screensavers
which did not come with windows but were downloaded from elsewhere; but I am
also sure there were some that came with the OS that were just as bad.

Steve Harris



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Re: Mersenne: idea for a new prime95 version

2001-02-04 Thread Russel Brooks

Idea for a screensaver for Prime95, let the user specify a
directory of picture files and Prime would pick one to display
every few minutes.  Decoding a JPG or GIF would suck up some
cycles but between picture updates Prime would get them all.

Cheers... Russ

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