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 2009-02-14, 10:01 #1 Cruelty     May 2005 65C16 Posts Other news
2009-02-14, 12:20   #2
henryzz
Just call me Henry

"David"
Sep 2007
Liverpool (GMT/BST)

10111011000012 Posts

Quote:
 Originally Posted by Cruelty PrimeGrid partners with 12121 Search
I have just noticed that primegrid seems to be using sr2sieve for all its sieving even when it could be using sr1sieve.
Is this me just being blind?

 2009-02-14, 18:51 #3 VBCurtis     "Curtis" Feb 2005 Riverside, CA 17×311 Posts Well, if you click on the sieve reservation link from the link cruelty provided, they clearly state they are using sr1sieve right now. What makes you think they are using sr2 for single-k searches? -Curtis
2009-02-14, 20:14   #4
henryzz
Just call me Henry

"David"
Sep 2007
Liverpool (GMT/BST)

32×5×7×19 Posts

Quote:
 Originally Posted by VBCurtis Well, if you click on the sieve reservation link from the link cruelty provided, they clearly state they are using sr1sieve right now. What makes you think they are using sr2 for single-k searches? -Curtis
the first post of that thread has been changed since
look at the second post a person gives a command including sr2sieve
i suspect that the organizer has realized and is trying to sort it out

 2009-05-10, 16:46 #5 VBCurtis     "Curtis" Feb 2005 Riverside, CA 17·311 Posts http://science.slashdot.org/article..../05/10/1322207 I'm not sure how surprising this is, but such patterns are fun to discuss.
 2009-05-11, 17:07 #7 Mini-Geek Account Deleted     "Tim Sorbera" Aug 2006 San Antonio, TX USA 10000101101012 Posts Gary, your example for your argument is slightly misleading: if we count from 1 to 200, it's accurate, but we are only considering primes, so it's the same as saying 2 to 199 since 1 and 200 are automatically eliminated. Also, as you later state, that's the most extreme possible scenario. Gary, see my prime counting here: http://www.noprimeleftbehind.net/for...?p=130#post130 My second table does indeed succumb to the problem you stated of ending our counting at an unfair location. pi(10,000,000) is 179,424,673, so everything from 100,000,000 (which is pi(5,761,455); finding all this at http://primes.utm.edu/nthprime/ BTW, a very useful page for finding this stuff ) up automatically starts with 1, similar to your worst-case scenario of 199. Indeed, for most fairly small round numbers x of pi(x), pi(x) is just above a power of 10 and so will give quite inflated figures But, if we instead count the primes between 10^a and 10^b, (a and b integers, whether a=0 or a=b-1 or whatever) we are instead left with the most extreme scenario in the opposite direction, that of no artificial inflation. My first table counts between 10^6 and 10^7, and does show a small but definite preference toward lower starting values, for obvious reasons. And the article states that the researchers were counting between 1 and 10^d, so they avoided the problem you stated. (whether or not they recognized the problem of counting the leading digits in the first 10^x numbers and intentionally avoided it or just didn't think about it at all, I do not know) Last fiddled with by Mini-Geek on 2009-05-11 at 17:11
 2009-05-19, 02:49 #8 gd_barnes     May 2007 Kansas; USA 29EB16 Posts But the article also referred to what, in effect, are counting numbers; i.e. electric bills, stock prices, population counts, etc. In that case, my calculations should be close. In the case of primes, the difference is much smaller between a starting digit of 1 and 9. That occurs for a similar reason: The primes starting with a 1 are smaller than the primes starting with a 9 and hence have a greater chance of being prime, albeit that amount of "greater chance" is relatively small; especially as the # of digits becomes large. Last fiddled with by gd_barnes on 2009-05-19 at 03:05
 2009-05-19, 02:57 #9 gd_barnes     May 2007 Kansas; USA 3·72·73 Posts I just wanted to say congrats to RPS for maintaining the top spot on # of primes! That was a lot of drives you guys have put out to maintain it. Barring a miracle (for us), it's doubtful that NPLB will be able to catch up now. As Carlos stated in another thread, likely PrimeGrid will pass us both; I'm thinking within 3 months or so. I think the top-5000 site needs a separate listing for BOINC and non-BOINC projects. It would make things more interesting. One thing that I, and I'm sure Karsten, would like to see is the non-top-5000 portion of the k's that you're searching filled in. It certainly makes for less messy Rieselprime.de pages. Just thought I'd bring that up. I believe that Karsten does a lot of searching on his own to fill in range for various k's searched by individuals and drives so I'm sure he'd appreciate some help with it. Gary Last fiddled with by gd_barnes on 2009-05-19 at 03:08
 2009-05-19, 07:15 #10 Kosmaj     Nov 2003 2·1,811 Posts Thank you. With limited resources, we are doing what we can.
2009-05-19, 18:17   #11
em99010pepe

Sep 2004

54168 Posts

Quote:
 Originally Posted by gd_barnes I think the top-5000 site needs a separate listing for BOINC and non-BOINC projects. It would make things more interesting.

Always trying to change the rules when you are not happy....

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