20060329, 18:24  #34 
Dec 2004
299_{10} Posts 
Agreed,
I did not mean to imply that increasing b2 bounds by 40% will increase your chances of finding a factor by 40% that's certain. What I did want to say is that "increasing the B2 bounds by 40% will increase the time for that curve by roughly 40%". It just wasn't a fair comparision between the two versions with different bounds. I'm uncertain why the beta client uses larger bounds by default although I'm glad to see it doing so. I've always ran a large B2 since stage2 seems to run significantly faster than the old days of B2=100xB1, especially on dual channel boards with sufficient memory. If both clients are running the same speeds with the same bounds I'm uncertain about the improvments. Not being harsh here or anything I just havn't followed the discussion. Last fiddled with by VJS on 20060329 at 18:25 
20060329, 22:00  #35  
Jul 2004
Potsdam, Germany
3·277 Posts 
Quote:
But it's true that different composites prefer different gmpecm variants. Yesterday, I tested the M1071.C205 with my PentiumM. Result: Stage1: 6.1 enableasmredc was fastest, then 6.0.1, then 6.1  but they differ by 1.5% from first to last. Stage2: 6.1 (both) are ~15% faster than 6.0.1 But then I put them on 55459*2^1666+1 (507 digits). Here, gmpecm 6.0.1 (with gmp4.2) was fastest for stage2  by ~20%! Seems like we either find a good way to determine which variant is the best for certain numbers, or we have to benchmark once we start ECM work on a "new" composite. I'll soon test the gwnum variant. And it really gets interesting once someone plays around with "tune". 

20060329, 22:05  #36  
Jul 2004
Potsdam, Germany
3·277 Posts 
Quote:


20060330, 17:30  #37  
Sep 2004
5×37 Posts 
Quote:
For larger numbers, I do agree with you that the improvement isn't so spectacular (but we have tested only two composites with a single B1=3e6 and I am sure that the developpers have reasons for their choices)!! Let's wait for the final gmpecm 6.1 release . Philippe. 

20060330, 18:56  #38 
Oct 2004
Austria
100110110010_{2} Posts 
A few curves on M1061 (time in milliseconds) at B1=110M
Code:
P95, B2=default  GMPECM (4.2/6.0.1), B2=100*B1 Kurve Step 1 Step 2 Step 1 Step 2 1 1571005 194096 3223343 98944 2 1570854 194047 3248428 98974 3 1570851 193983 3229012 99322  average 1570903 194042  3233594 99080 Last fiddled with by Andi47 on 20060330 at 19:00 
20060331, 04:30  #39  
"Nancy"
Aug 2002
Alexandria
2,467 Posts 
Quote:
Thanks, Alex 

20060331, 14:46  #40 
Oct 2004
Austria
2·17·73 Posts 
Code:
GMPECM 6.0.1 [powered by GMP 4.2] [ECM] Input number is 2^10611 (320 digits) Using B1=110000000, B2=4290000000, polynomial Dickson(6), sigma=4229074309 Step 1 took 3224970ms Step 2 took 48658ms Run 2 out of 25: Using B1=110000000, B2=4290000000, polynomial Dickson(6), sigma=4059283320 Step 1 took 3233083ms Step 2 took 48797ms Run 3 out of 25: Using B1=110000000, B2=4290000000, polynomial Dickson(6), sigma=3225355689 Step 1 took 3256811ms Step 2 took 48855ms 
20060331, 16:08  #41  
"Bob Silverman"
Nov 2003
North of Boston
7506_{10} Posts 
Quote:
I would suggest using larger step 2 limits. It is optimal to spend the same amount of time in step 1 and step 2. This is independent of the speed of the computer. 

20060331, 17:07  #42  
Jan 2005
2×31 Posts 
Quote:


20060331, 20:51  #43  
"Nancy"
Aug 2002
Alexandria
4643_{8} Posts 
Quote:
Alex 

20060331, 22:10  #44  
Oct 2004
Austria
9B2_{16} Posts 
Quote:

