Mersenne Digest Tuesday, April 27 1999 Volume 01 : Number 549 ---------------------------------------------------------------------- Date: Fri, 23 Apr 1999 21:04:27 +0200 From: "Steinar H. Gunderson" <[EMAIL PROTECTED]> Subject: Mersenne: Re: Mersenne Digest V1 #548 On Thu, Apr 22, 1999 at 04:16:54PM -0700, Mersenne Digest wrote: >Well, my assumption is that GCC doesn't do 64-bit... I wish I were a Ultra >guru like the one that did the DES port for Distributed.net... that thing >flies! I was getting > 24Million keys/sec on just that one Quad machine... >The Quad Xeons were only getting 16 Million... :P Give me an UltraSPARC, and I'll promise to learn its asm ;-) Well, I guess gcc _should_ do 64-bit, if the code itself knows about it (ie. uses `int' and assumes it's 64 bits). >Actually, surprisingly, the CE devices should do pretty well... (Just keep >'em charged!) >For example, the Jornada 820 we have here at the office has a 190Mhz >StrongArm SH3 processor in it... Wow! I really didn't know that. But won't that mean they drain battery? I mean, the Psion 5 series (which some of my friends have; really impressive) use standard AA batteries. Do the WinCE machines? >The only concern I have is memory on the CE devices... George is said to be working on a (slower) low-memory mode for Prime95 v19 (hmmm, what is the official name? Prime95? mprime? Prime? GIMPS?). >Comparisons for you: >- ---Sun UltraSparc (not sure what speed, 240?) >P=19937 >- --MacLucasUNIX >15.929sec = .0007s/iteration >- --JavaLucas (JDK 1.2) >128.348sec = .006s/iteration Very surprising... Jun made Java, didn't they? This was extremely slow, compared to the native version. >- ---Intel P2-412 Overclocked? >- --Lucas >50.11sec = .0025s/iteration Compiled with what? Standard gcc? egcs? Pentium GCC? `-O6 -march=pentiumpro' should give a fair bit of performance increase (in my own, small, string-based programs I've noticed as much as +30% vs. gcc 2.7.2.3). >I'd try it on that AS/400, but I hate the damn thing... Just send it to me, I'd be happy... >So... there is an order of magnitude difference between MacLucasUNIX and >JavaLucas, but not between Lucas and JavaLucas... So I guess I shoulda >ported from MacLucasUNIX (I just wanted to do a sanity check for myself >first)... You couldn't send me the JavaLucas source? I used to be a pretty good Java coder (although I don't have a Java compiler anymore (can't get the stupid Linux JDK to work)), so I could perhaps see if you had done something _really_ stupid ;-) >Actually, looking at the JavaLucas vs Prime95 for a big P (6466417), I'm >getting 3.3s/iteration vs. .02s/iteration... So 2 orders of magnitude... >I think that sounds right... Prime95 is fast. We all knew that ;-) George had some C code once, nobody could ask him? (OK, I know it was based on lucas.c or something, but I guess he still have made something smarter out of it.) >Actually, the Sega Dreamcast will run on WinCE Yuck... What a stupid idea... or? (Sorry, I think defining something as a subset of the Win32 API is just plain stupid.) >Sony or someone will have a console running >JavaOS... (WACKY aint it?) I think the idea of WinCE on microwaves is even more wacky. Imagine your microwave crashing... >Duh... of course threading on one CPU won't make it faster, slower is more >likely... Yup. Most people _still_ don't realize that. >I'd like to see if I can get the FFT code to multithread tho. That'd be >cool... Test single prime faster at least, but I don't know if there are any >parallel FFT algorithms... Pointers anyone? I'm not sure if it would really be worth it. Lots of extra programming pain and CPU intercommunication (which is slow), for no real increase in computing speed. >****** >Actually, I don't really know anything about FFTs, so any help would be >appreciated... I have come to realize that I need to brush up a bit on my >math... Its been too long since college... >****** Ummm, me neither. (I've just started on matrix calculation, but I guess I'm still 4 years ahead of the schedule.) >Plus, you could coordinate a buncha Java clients running around and stuff >pretty easily... Yes, the Java networking API is fantastic. (I programmed an IRC bot to Java once, and it was fantastic...) - --- snip --- [WinCE:] >Multithreading (?) On a WinCE machine? /* Steinar */ ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ Date: Fri, 23 Apr 1999 18:26:54 -0400 (EDT) From: Jason Stratos Papadopoulos <[EMAIL PROTECTED]> Subject: Re: Mersenne: Re: Mersenne Digest V1 #548 On Fri, 23 Apr 1999, Steinar H. Gunderson wrote: > On Thu, Apr 22, 1999 at 04:16:54PM -0700, Mersenne Digest wrote: > >Well, my assumption is that GCC doesn't do 64-bit... I wish I were a Ultra > >guru like the one that did the DES port for Distributed.net... that thing > >flies! I was getting > 24Million keys/sec on just that one Quad machine... > >The Quad Xeons were only getting 16 Million... :P > > Give me an UltraSPARC, and I'll promise to learn its asm ;-) Well, I guess > gcc _should_ do 64-bit, if the code itself knows about it (ie. uses `int' > and assumes it's 64 bits). > gcc won't use 64-bit data types on the Ultra (except floating point). egcs will, but I haven't used it. gcc actually generates terrible code for the UltraSPARC series...its authors apparently never bothered with code generation for better than a sparc 2. Also, I've found that an Ultra of a certain speed is usually equivalent to a Pentium II of about twice the megahertz. The key-cracking engine is so fast because modern ultras have a version of MMX that can do much more in the way of logical ops, works completely in parallel with the integer unit, and has 32 registers to play with. x86 could have been like this, which makes me sad. > I think the idea of WinCE on microwaves is even more wacky. Imagine your > microwave crashing... > Were you the guy on the RC5 list that wanted key cracking engines for things like laser printers and Furbees? Man, I thought *I* was strange. (PS: I looked in a postscript guide; RC5 would be *real* tough to do :) > >I'd like to see if I can get the FFT code to multithread tho. That'd be > >cool... Test single prime faster at least, but I don't know if there are any > >parallel FFT algorithms... Pointers anyone? > > I'm not sure if it would really be worth it. Lots of extra programming pain > and CPU intercommunication (which is slow), for no real increase in computing > speed. There are several standard tricks for computing an FFT in parallel. The seminal paper in the field is Bailey's "FFTs in External and Hierarchical Memory", available on the web somewhere. On an SMP with separate caches the parallel methods would probably rock'n'roll. jasonp ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ Date: Sat, 24 Apr 1999 18:14:34 -0400 From: "Ernst W. Mayer" <[EMAIL PROTECTED]> Subject: Mersenne: setting up a Windows service I have a DOS executable that I need to run on a Windows 95 system as unobtrusively as possible, i.e. I'd like to be able to lauch it at idle priority and then have it be invisible to other users, much like on can do with Prime 95. Could someone with Windows programming experience help me out with this? Thanks, Ernst ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ Date: Tue, 27 Apr 1999 17:05:00 +0100 (BST) From: Chris Jefferson <[EMAIL PROTECTED]> Subject: Mersenne: PrimeNT Hi! I'm sure this is asked time and time agai, but I'm new, so could someone point me in the right directio to install and maintain NTPrime over a large number of computers from an NT Server. Is it possible? if not, what is the best way to go about setting it up on a large number of machines (That have to be secure..)? - ------------------------------------ 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.... - ------------------------------------ ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ End of Mersenne Digest V1 #549 ******************************
