factoring request
in [Math]
|
Prev: Typography: Choosing Century Expanded?
Next: Considering the forces of computation: questions for the group, I have three:
From: dan73 on 1 Dec 2009 04:56 >i7 processors are quad-core but each core can run 2 >threads. This makes it sort of eight-core. >Since ggnfs+msieve allow to allocate CPUs and Threads >to a job then i was running at full speed (near 100% >CPU utilization). >My operating system is Windows 7 64-bit and have used >the 64-bit binaries of the software. >A Pentium 4 3.0 would probably be much slower, at least >1 day to factor that number with the same software. Thanks for the explanation. The latest in hardware and software is surely far beyond what I have. That is about the time frame I came up with for a pentium 4. Still a lot faster than 14 days for ECM. Thanks, Dan
From: dan73 on 1 Dec 2009 04:58 >> I like to experiment with different factoring methods >> but to be quite honest a lot of these factoring >> algorithms are way over my head. >Ignorance is a curable disease. >Run, don't walk, and get a copy of: >Crandall & Pomerance, Prime Numbers, A computational >Perspective. >Read it. It will teach you all about modern factoring >methods. >It is an excellent book. Thanks! Dan
From: Phil Carmody on 1 Dec 2009 17:00 Pubkeybreaker <pubkeybreaker(a)aol.com> writes: > On Dec 1, 8:32�am, dan73 <fasttrac...(a)att.net> wrote: > > I like to experiment with different factoring methods > > but to be quite honest a lot of these factoring > > algorithms are way over my head. > > Ignorance is a curable disease. > > Run, don't walk, and get a copy of: > > Crandall & Pomerance, Prime Numbers, A computational Perspective. If, due to its popularity, it's checked out of your local library, then Hans Riesel's Prime Numbers and Computer Methods for Factorisation is almost as good. It doesn't cover as much as PNaCP, but the places it falls short are not the ones that you will need to worry about until you're familiar enough with the field to be able to resort to primary source material rather than PNaCP. > Read it. It will teach you all about modern factoring methods. > It is an excellent book. My above paragraph might appear to say the contrary, but it doesn't. PNaCP is a stunning book. It was one of the books that needed to be written. Phil -- Any true emperor never needs to wear clothes. -- Devany on r.a.s.f1
From: Tim Little on 1 Dec 2009 18:59 On 2009-12-01, factorboy13 <temp15(a)atelierweb.com> wrote: > i7 processors are quad-core but each core can run 2 threads. This > makes it sort of eight-core. Usually quite poorly, as there are plenty of internal bottlenecks preventing full-speed execution of two threads. It's probably more like 4.5 cores in the best case, but could even be less than 4 as hyperthreading tends to evict cache faster and can stall both threads more often. - Tim
From: factorboy13 on 1 Dec 2009 23:03
> On 2009-12-01, factorboy13 <temp15(a)atelierweb.com> > wrote: > > Usually quite poorly, as there are plenty of internal > bottlenecks > preventing full-speed execution of two threads. It's > probably more > like 4.5 cores in the best case, but could even be > less than 4 as Well, I run factorization tests both on it and on an old Core2 2600 (2 cores/2threads) and the I7 (4cores/8threads) is more than 3x faster. Also ran factorizations with a dual CPU Xeon 3.0 that does hiperthreading (then 4 threads), but this one is much slower than the Core2, probably the sole reason is that it running 32-bit binaries (cannot support 64-bit OS). I can only be happy with the i7 |