20021213, 14:06  #1 
Sep 2002
3^{2}×13 Posts 
Probability of finding a factor in DC p1
I've recently been adding some older machines running DCs for me, and I just got a factor in a p1 test. Considering that most of these should already be factored in the initial test, was this a fluke (perhaps a machine that didn't have enough memory to run p1 completed the first test) or should I expect all of my DCs to have an equal chance of finding a factor in p1 testing?

20021213, 14:59  #2 
Dec 2002
Frederick County, MD
172_{16} Posts 
Perhaps this is an ignorant question, but what is a DC? :?

20021213, 17:24  #3 
P90 years forever!
Aug 2002
Yeehaw, FL
7407_{10} Posts 
DC = doublecheck
Most numbers being doublechecked did not have P1 run. P1 factoring was added in version 20, I think. So all your doublechecks should have an equal chance at finding a factor. Also, prime95 should be smart enough to skip P1 factoring if it has already been done. 
20021225, 05:48  #4 
"Richard B. Woods"
Aug 2002
Wisconsin USA
2^{2}·3·641 Posts 
It looks like firstrun LL assignments started routinely including P1 factoring after trial factoring at roughly exponent 10 million.
DCs are now being assigned in the 88xxxxx range. It took ten months for DC assignments to advance from 76xxxxx to 88xxxxx, so I guess that new DC assignments will usually first do a P1 for most of the next year, unless separate P1 assignments are implemented in Primenet earlier. 
20021225, 06:06  #5  
"Richard B. Woods"
Aug 2002
Wisconsin USA
7692_{10} Posts 
Quote:
Only stage 2 requires the extra (beyond the default of 8M, that is) memory you specify in Prime95's Options/CPU.../"Daytime available memory" and "Nighttime available memory". (Also, ECM factoring requires this extra memory.) 

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