RE: Mersenne: Prime95 as an NT/2000/XP service
It would be way cool for it to have a WMI interface. That's the "correct" way for a service to show some GUI, and its not too terribly hard to code... Plus it makes it so you can show the GUI across the network etc etc.. So if I wanna see how computer "USWEST_PRIME_CRUNCHER" (inside joke, sorry bro), I can connect to it and see it via the WMI interface stuff via the MS Management Console. -Jeremy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of George Woltman Sent: Tuesday, June 25, 2002 11:46 PM To: [EMAIL PROTECTED] Subject: Mersenne: Prime95 as an NT/2000/XP service I've spent a few days fighting with Windows and MFC to make Prime95 run as a true Windows NT Service. That is, when you check the "Start at Bootup" menu choice, prime95 is installed as a service. At next bootup it starts before anyone logs in. At first login, the familiar red icon appears in the system tray, and prime95 keeps running even when you log off. This question is for the serious NT sysadmins out there: Given that Microsoft strongly discourages NT services having a GUI interface, are there any problems or security issues I need to worry about? A GUI service must run under the Local System account. You can still use Hide Icon to make the service virtually invisible to all users. Even if there are problems, I think this will work well for naive home users running WinXP with multiple user accounts. My hope is to eliminate the NTsetup and NTPrime programs with this feature. _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: slaying cpus with prime95
Crazy thought here, but what if prime95 only ran at x% speed? For example, put some hlts in there and see how that affects the CPU temp. I think for those of us that run Prime95 on laptops find it unnerving when the fans are running full blast all the time, and it would be cool to have a cooler running prime95 rather than no prime95 at all. Thinking about it, you could probably keep the temp down to around normal idle temp... -Jeremy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Nick Craig-Wood Sent: Monday, January 14, 2002 4:26 PM To: [EMAIL PROTECTED]; Steve Elias Subject: Re: Mersenne: slaying cpus with prime95 On Mon, Jan 14, 2002 at 02:45:21PM -0500, Steve Elias wrote: > here are some instances where i have damaged computers > by (capriciously?) running prime95! > > 1 - i just got my wife's toshiba laptop back from toshiba warranty > service. running prime95 for ~6 months on it caused the fan to die, > and then the laptop would overheat & shutdown even without prime95 > running. apparently the heat caused lots of disk badblocks too. Mmm, yes the fan on my laptop (Dell 38000) sounds like someone dumped a load of grit in it - not good :-( I stopped running prime95 (mprime actually) on it for that reason. -- Nick Craig-Wood [EMAIL PROTECTED] _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: Just curious
Make that "drives" not "drivers"... And think, its only Wed. -Jeremy _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: Just curious
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Aaron Blosser Sent: Wednesday, April 19, 2000 12:18 PM To: Mersenne@Base. Com Subject: RE: Mersenne: Just curious >For what it's worth... > >I've heard that referred to as "stiction" :) There's a decent enough >solution to the problem of "stuck" drive heads, but you really should be >absolutely sure that's what the problem is... > >Drives have a "landing zone" or parking area where the heads will move to >when it's powered down. There's no data on that part of the track, so if >your heads do get stuck there when it's turned off, there's something you >can try... > >Again, be sure that's really what the problem is before trying this... :) > >But, in short, with the drive powered on and making the "hey, my heads are >stuck!" noise, you gently rap the drive on a hard surface. Rap it harder >and harder until finally you hear the heads moving about normally. Usually, >the head will unstick itself and as long as the head wasn't actually >damaged, you may have just enough time to get your data backed up pronto. > >Jeremy and I used to do that alot on those first generation IDE drives >(which seemed to have this problem much more often) back when we were >computer techs... It sounds funny, I know, but it worked great most of the >time. > If I remember correctly, it seemed to happen with certain batches of drivers. Like a batch of WD drivers and then later maybe Maxtor or whatever. And there was *always* the same problem in that it would spin up and then right back down again at boot (usually the first boot). So I think it was more of a shipping or drive problem or something more than anything. But, as a last ditch effort it works... In reality tho, I think that what is *more* common is the actual controller or PCB on the drive starts to flake out before an actual problem w/ the platters etc. Usually, if it is a platter/head problem its usually due to abuse (such as dropping something heavy on your drive while its reading/writing). I'll never forget the times when we would do data recovery of a bad drive by putting it in the freezer for 30 mins, which we *theorized* shrank the PCB on the HD thus fixing some stress fracture or whatever temporarily (long enough to get the data off the drive before it heated back up again). Just remember the following is ONLY recommended if you are trying last ditch type of things and don't want to spend the $$$ sending it off to a *REAL* data recovery type of place. >For what it's worth, modern drives rarely have this problem. Even the >10,000 RPM drives which get QUITE hot during use have good landing zone >areas where the heads aren't likely to come into contact with the hot >platters. _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: pi
I think the mistake you are making is that the *precision* of PI is infinite (never ending), but PI itself is not "infinity". 3.14159.->ininite number of numbers Since it is 3.something we know it is > 3 and < 4. Take 1/3 for example. Its decimal value us 0.3-> infinte # of 3's But it is < 3 and > 0. Just because the number of 3's in it is infinite does not mean it is "infinity". _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Where's the flaw in my thinking?
Okay, I was sitting there the other day thinking about a non-FFT squaring algorithm... Say we have 14, which in binary is 1110... If we left shift this by the position of the 1, for each 1 in the binary representation, and add them together, we should get the square... So to square 14, we do this: 1110 << 3 == 111 + 1110 << 2 == 0111000 + 1110 << 1 == 0011100 + == 11000100 which is 196 So for each squaring, we have x left shifts and adds, where x is no larger that p. In any case... is this just me being dumb and missing that this is just a stupid way of squaring a number? _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: pi
Actually bro, I highly doubt the Universe is spherical. If one is to believe in the concept of gravity bending space-time, then the Universe would be more akin to some bubbly, blobby, amorphous structure (see http://www.sciam.com/1999/0699issue/0699landy.html) Interestingly enough, you could conceptually have "bubbles" in space-time which are cut off from the rest of the universe. Anyway, back to Pi... I think that the major issue is that we look at a circle and think of some number of units, atoms, particles, whatever... However, we neglect the fact that a circle isn't constituted of particles... This seems to been some weird human characteristic, we think of everything in units (time for example)... Take the function y=x, there are an infinite number of points on that line... Even, if I limit the range of x from (-1,1), there are still an infinite number of points on that line... So even the simple function y=x has infinite precision, yet I can precisely determine that the length of that line is 2*sqrt(2). -Original Message- From: Aaron Blosser [mailto:[EMAIL PROTECTED]] Sent: Wednesday, February 09, 2000 8:41 AM To: Mersenne@Base. Com Subject: RE: Mersenne: pi > The problem isn't that Pi isn't finite, it's less than 4 so it's finite. > The problem isn't that it isn't exact. > The problem is that it can't be represented exactly in decimals which mens > that when we write the expansion, we'll always have to make do with an > approximation to the exact value. Consider this: Let's assume that the universe is spherical (a logical assumption if we assume it's the result of a currently expanding explosion xx years ago). If we were to calculate the radius of this sphere down to a single atomic width, using some decently expanded version of pi would could come up with an exact number for the volume of the universe. What I'm getting at is that at some point, pi reaches a practical limit at which expanding more decimal points is an abstraction because we could never measure anything large enough for it to be useful. I mean, c'mon! The universe is only so big! :-) Being in a hurry, I don't have the time to figure out how many decimal places that would be...perhaps someone more adventurous would care to give it a go. Aaron _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: SMP GIMPSing And Sharing The Burden
>>Parallel FFTs typically have three steps: 1) crunch like mad on local >>data, 2) global scatter-gather (everybody trades data with everybody >>else), 3) crunch like mad on local data. In the GIMPS case, you want >>an inverse FFT too, so that the order is 12321. With the real FFTs that >>Prime95 uses it's worse...step 3 has some global communication too. >>The communicaton is much more a problem for systems with distributed >>memory, but since speed is of the essence here the communication means >>cache thrashing. Running two processors in parallel will speed things up, >>but I would think that the speedup wouldn't be as great as running two >>copies of Prime95. You could probably get some cool single machine >>statistics though :) > >Wouldn't this help tremendously the problem of having to do enormous >10-million digit primes? > >I'm guessing, a client hasn't been attempted, but I'd certainly love to have >one. I have way too many machines that are Dual and Quad Processor Intels that >could seriously take advantage of this. Well, I'd say that the main problem with try to parallelize the FFT process is that it ain't so easy to do, and isn't really worth it in the long run (i.e. Run 2 copies of Prime95). a) 99.9% of the math in Prime95 is done using assembly. And multi-threading w/ assembly isn't exactly easy. b) Depending on the FFT size, there a several optimizations that could be used. (Such as radix-4 or radix-8 FFTs) c) The cost of inter-process communications outweights any performance gains. A while back, I thought up a non-FFT algorithm that would be worst case O(N log N), but I need to work on it a little more to make sure I'm not crazy... _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: FW: what do you think about the authenticity of this?
Ah, good 'old urban legends... "This wonderful bit of creative writing began circulating on the Internet in April 1998. Written by Mark Boslough as an April Fool's parody on legislative and school board attacks on evolution in New Mexico, the author took real statements from New Mexican legislators and school board members supporting creationism and recast them into a fictional account detailing how Alabama legislators had passed a law calling for the value of pi to be set to the "Biblical value" of 3.0. This brilliant piece of humor was originally posted to the newsgroup talk.origins on 1 April 1998 as well as sent to a list of New Mexican scientists and citizens interested in evolution and printed in the April issue of the New Mexicans for Science and Reason newsletter NMSR Reports. Its talk.origins poster followed up a day later with a full confession and explanation of the prank, thereby allowing others to share in the fun. One would have thought that would have been the end of it. Ah but the Internet works in mysterious ways. Several readers forwarded the piece to friends and posted it to other newsgroups. As the story moved along, what would have easily identified it as a parody and not a news item was stripped out: the attribution to "April Holiday" of the "Associmated Press." Now it looked like a real news piece. Which is how it was received by many. There is not now and never has been a bill in front of the Alabama state legislature to redefine the value of pi. With one exception, none of the names given in this fanciful account stand up to scrutiny. The one exception is Guy Hunt. He is a former governor of Alabama, convicted in 1993 for diverting $200,000 from his inaugural fund to his personal use. Though the claim about the Alabama state legislature is pure nonsense, it is similar to an event that happened more than a century ago. In 1897 the Indiana House of Representatives unanimously passed a measure redefining the area of a circle and the value of pi. (House Bill no. 246, introduced by Rep. Taylor I. Record.) The bill died in the state Senate." For more funny urban legends, I suggest visiting http://www.snopes.com Jeremy Blosser -Original Message- From: Olivier Langlois [mailto:[EMAIL PROTECTED]] Sent: Friday, February 04, 2000 3:15 AM To: Mersenne mailing list (E-mail) Subject: Mersenne: FW: what do you think about the authenticity of this? Is this story really ?? Where is going our society ?? :-) _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
