20050728, 22:28  #1 
Jun 2003
11000110011_{2} Posts 
New Sieve Thread Discussion
Lars,
I was wondering that has anyone found any factors that proth_Sieve previously missed? Could you post them below! Thanks, Citrix 
20050728, 22:40  #2 
Sep 2004
2×5×283 Posts 
Citrix,
Lars told me one week ago (16 Jul) that my ranges found already 19 missed factors where we have no PRP test yet. In Lars ranges he found one. (All missed factor where n>2Mil) One more thing. I started the 9870099000 range with the old dat file and found the following factors: 98702674984699  90527*2^14752511+1 98705626374527  79817*2^3437591+1 98725913745839  237019*2^15283258+1 98728617700901  258317*2^13774959+1 Then I restarted it with the new dat file and 98701195679903  90527*2^22380191+1 98702674984699  90527*2^14752511+1 98703968070791  79817*2^35840703+1 98705626374527  79817*2^3437591+1 98707048330861  222361*2^35969432+1 98709139652681  214519*2^24565634+1 98710294034071  168451*2^47186640+1 98713092107897  222361*2^38408320+1 98719327707491  90527*2^39919751+1 98720039885147  90527*2^30822647+1 98720263609273  168451*2^44530128+1 98720326492903  90527*2^45747167+1 98723758825841  222113*2^30695621+1 98724565964807  222113*2^47054597+1 98725913745839  237019*2^15283258+1 98726907126721  222113*2^35183621+1 98727187829681  237019*2^36555406+1 98727258317549  222113*2^35498597+1 98728617700901  258317*2^13774959+1 Cheers, Carlos Last fiddled with by em99010pepe on 20050728 at 22:45 
20050729, 03:43  #3 
Jun 2003
3×23^{2} Posts 
If in 3T we just found 19 missed factors then I do not think it is worth double checking the dat ranges. May be we should just work on 2050M and then join the dats around 85T. We are also likely to find duplicate factors for these numbers, so there is no need to find the smallest factor.
If we agree to this it would double are sieving speed. Citrix 
20050729, 04:18  #4 
Jun 2005
101110101_{2} Posts 
We had about the same discussion at SoB, and we agreed not to give up doublecheck.
Did you think about the amount of time needed to run PRP for 20 numbers? It takes quite a while, I think more then the time spent for re sieve. IMHO, we should do this well, once for all, and not running the risk to regret something later. We will have sieved 4 G in the first month, so, if SoB finishes Firstpass sieving in 8 months, we will be at 40G, at that time. Thats fine, because it is about the level at which PSPsieve alone and SoB+PSP sieve at 60G will be the same efficient (for factor throughput). So, there is no hurry. The extend of the sieving range is something for the far future, anyway. No need to bother with short term speed increases. For the later ranges which will be done with SoB, I doubt if there is a necessity to do DC, because the SoB DC can show if there are missed factors (and eventual problems with hardware or submission). Yours H. 
20050729, 06:13  #5  
Sep 2004
2·5·283 Posts 
Quote:
Carlos 

20050729, 08:03  #6 
3^{2}×7×89 Posts 
31003300 reserved by shoelace
do you have a prefered range size or range completetion time? Last fiddled with by shoelace on 20050729 at 08:04 
20050729, 15:08  #7 
Dec 2004
453_{8} Posts 
Didn't ready through everything but...
 finding 19 factors in 1T doublecheck  Speed decrease by using 1k<n<50M compared to 20M<n<50M (33%??) Basically those 19 factors per T = 57 factors per T (time wise) That's pretty dense. Especially considering your planning on finding primes for 15k's. Also the chances of finding the second smallest factor when you missed the first one is not great. I think we only found about 3 or 4 of these with SoB. 
20050729, 16:02  #8 
Apr 2003
2^{2}×193 Posts 
Newest numbers:
Within the first 2.5 T we have found 33 lost factors. All these factors are above n=2Mil. But that was to be expected as we have already increased the sieving range from 2Mil to 20Mil and had a second pass for all values below 2Mil for the first 510T already. Lars 
20050729, 16:09  #9 
Apr 2003
1404_{8} Posts 
@shoelace:
I have no prefered range size. I am happy about each calculated result that i will not restrict the range reservation. For the completion time i like to see results latest after a month. If you want to reserve a range that needs longer then a month either send in intermediate results or send me a note that the range will take longer. Lars 
20050729, 17:06  #10  
May 2005
Copenhagen, Denmark
17^{2} Posts 
Quote:


20050729, 19:45  #11  
Jun 2003
3·23^{2} Posts 
Quote:
Citrix 

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