On 13 Jan 2002, at 21:37, Gerry Snyder wrote: > At home I have 2 PC's, both of which devote their spare cycles to GIMPS. > One is a 1.3 GHz P4 running W98, and the other a dual 1 GHz P3 running > linux. One of the P3's is doing LL testing, and the other is doing > mostly ECM, with a little trial factoring thrown in. > > The only part of Prime95 that uses the SSE2 P4 instructions is the LL > testing. Because of the huge speedup this gives, I would like to keep > the P4 machine doing nothing but LL tests. It is now about a month away > from finishing its first 10 megadigit candidate. > > My question is whether it is worth the trouble to shift the trial and > P-1 factoring of the next one to one of the P3 processors (the non-LL > one). It might lead to one extra LL test in two years.
You can do even better than that: Suppose the three processors are as follows: A wants to run trial factoring - if you run LL or P-1 on this, B slows down due to memory bus contention B doesn't mind running P-1 C wants to run LL only. Firstly you want to make sure that C doesn't have SequentialWorkToDo=1 in prime.ini (else TF & P-1 will be run before the current LL completes). Also make C's DaysOfWork greater than the time estimated to run TF & P-1 on A & B. Let C get a new assignment Test=<exponent>,N1,P and let N2 be the required factoring depth for that exponent. Edit the new assignment in C's worktodo.ini, replacing N1 by N2 and P by 1. If N1 < N2, trial factoring is required. Edit A's worktodo.ini file, adding a new line at the top Factor=<exponent>,N1. Stop & restart mprime on A to get the assignment started. If a factor is found, remove the assignment from C's worktodo.ini file & let C get a new assignment. Whatever happens, let A report the result of the trial factoring. If A fails to find a factor and P=0, P-1 factoring is required. Edit B's worktodo.ini file, adding a new line at the top Pfactor=<exponent>,N2,0. Stop & start mprime on B to get the assignment started. Let B report the result of the P-1 factoring. If a factor is found, remove the assignment from C's worktodo.ini file & let C get a new assignment. Regards Brian Beesley _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
