>-----Original Message----- >From: Steinar H. Gunderson [mailto:[EMAIL PROTECTED]] >Sent: Saturday, April 17, 1999 6:33 PM >To: [EMAIL PROTECTED] >Cc: [EMAIL PROTECTED] >Subject: Mersenne: Re: Mersenne Digest V1 #546 > > > >>He has it running on his Ultra Sparc but, as expected, it is >only running in >>32 bit. > >I'm sorry that I don't know about UltraSPARCs (but I would >give my left hand for one), but why is this the case? > 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 Plus, I'm not sure if the code is optimized for 64-bit... >>plus since it's Java, you could run it on your Windows CE device, or >>anything else with a Java engine. > >Running Prime95 on a Windows CE machine -- isn't that a bit >optimistic at the >moment? I mean, even my (erm, it's not mine) trusty old P60 >has problems now >(earlier I used to get some smaller exponents from George, but >now I guess >such small ones are only available for double checking). A >Windows CE version >would drain battery and just be overly slow. (I really hope it >was meant as a joke ;-) ) > 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... See Benchmarks Below... The only concern I have is memory on the CE devices... >>Is there a demand out there for a Java port? It wouldn't be >as fast as C or >>ASM for most platforms, but for platforms with NO port at all 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 ---Intel P2-412 P=19937 --Lucas 50.11sec = .0025s/iteration --JavaLucas (Jview) 52.797sec = .0026s/iteration --Prime95 .037s/iteration (Of course, the FFT is huge so its not a fair comparison :P) ---RS6000 P=19937 --JavaLucas (Bleh, this is slow... something went wrong here... no JIT?) 61.158sec = .003s/iteration I'd try it on that AS/400, but I hate the damn thing... (Its got 4 PPC 604e's in it tho) 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)... 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... > >Like consoles? ;-) (OK, they don't run Java.) > Actually, the Sega Dreamcast will run on WinCE, so I assume Java support will be there... Also, I think it is ummm... Sony or someone will have a console running JavaOS... (WACKY aint it?) Plus, think about all the phones, toasters, microwaves and doorstops coming out that run Java... >But I think this might be interesting, not only for >non-ported-to platforms. >I think we just discussed this, but it would be nice (for >newcomers) to load >a page (any page -- this applet could be spread on thousands >of users' pages) >with a factoring applet on, and get the message `Thank you for >contributing >some CPU time to GIMPS. Click here to find out more.'. > >--- snip --- > >>You may be surprised at just how fast a Java implementation could be. > >Yes, especially with JIT compilers. (Wasn't Java really made >to be quite fast? >I can still remember when I had just received the JDK, and used it for >almost everything... Because it beat VB (4.0) hands down, at >least when it >came to speed.) > >>He's doing some work on it to optimize it now and promises to have it >>multithreading in no time. Hmm. His initial timings were >based on the >>Ultra Sparc running MacLucasUNIX. For example, M(3217) was >only 17% slower >>with Java than with the C code. Actually, it was on my P2-300 against Lucas.c, and I've caught up with that... On to MacLucas... :) > >Multithreading? > >Key rule: For a system with only one CPU, multithreading will >not make it >faster. But who knows, those monsters may have 256 of them, >for all I know. >At least they're expensive enough. > Duh... of course threading on one CPU won't make it faster, slower is more likely... But when you have a lot of SMP machines sitting around, its more fun to run just one proggy rather than 4 or 12 or 24 ;) 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? ****** 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... ****** Plus, you could coordinate a buncha Java clients running around and stuff pretty easily... Anyway, there's work to be done, but I thought I'd post some figures that I have to date... ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
