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1) Message boards : Problems and Help : host identifier.... (Message 15691)
Posted 4506 days ago by Profile UBT - lordnikon
anyone? am i gonna have to detach, re-install and the re-attach?
2) Message boards : Problems and Help : host identifier.... (Message 15645)
Posted 4509 days ago by Profile UBT - lordnikon
hi all....

i seem to have 2 systems on here which are sharing the same identifier....even tho they are 2 seperate platforms.... i think it might have been from a merge a while back....

its not a major issue on here but becomes apparent on places like boinc stats etc....

is there a way to fix this?
3) Message boards : Number crunching : hardware for different apps (Message 14251)
Posted 4579 days ago by Profile UBT - lordnikon
Whilst I won't disagree with that overhead figure per se, my experience with a dual-core box running with -t2 is that both cores are not fully utilised, even accounting for the parent thread using a small amount of CPU (~0.5% from memory).

The way the threading is currently done in sr2sieve and gcwsieve is that -t2 allows the main part of the algorithm to be worked on concurrently by two child threads, but the prime number sieve is performed by the parent thread which hands out batches of primes to the children to work on.

This model reduces total memory footprint because usually it is the prime number generator that uses most of the memory, but it means that there will be times when both children finish their batch of primes and are both waiting in a queue for the single parent to generate more.

I am working on another model in which each child thread will generate its own prime numbers, so there will be no parent thread. This will use more memory, but less than running two separate processes because some of it can be shared.

Wow thanks a ton for the answers from everyone above especially you Geoff. I am very interested and think your on to something with the idea of a model in which there will be no parent thread, I am curious to see if this would be faster too :) Well I know a few people now to PM when I have the cash in hand to purchase the next computer to PM to talk about parts that I am interested in and what your suggestions are. Till then which will more then likely be this summer, Thanks a ton for the answers and for helping the other peoples questions in this thread. /salute

yeah man, thanks to Vato, geoff, ward and John!
4) Message boards : Number crunching : hardware for different apps (Message 14241)
Posted 4579 days ago by Profile UBT - lordnikon
Hey guys, thanks for the answers they are great.... its kinda what i thought.. especially with the whole multi processing single tasks... i was wondering if you'd get sum extra leetness cos of the multi processing.

so what is is that LLRs are really after, is it the pure grunt behind a really fast CPU? more iterations you can do the faster it gets done stylee....


PG forums RAWK
5) Message boards : Number crunching : hardware for different apps (Message 14215)
Posted 4580 days ago by Profile UBT - lordnikon
hi all,

I know that 64 bit system are better for sieveing but was wndering if it was just the fact that the OS can address more ram or wether it also has to do with the fact that the larger servers that use the 64 bit architecture have wider data/address busses too?

also i've seen posted that the quad and dual core machines are especially good for sieveing... is this just becuase you can run 8 tasks at once or do actually get to go thru more work than 8 individual core running at the same speed.

also how useful is the cache that the CPUs have for these tasks...

sorry for the questions so rapid fire... just slowly trying to get to grips with the whole cruching thing...

any tips/pointers/tutors would be appreciated.


6) Message boards : Proth Prime Search : PPS Sieve (Message 14000)
Posted 4585 days ago by Profile UBT - lordnikon
lo lo... just put a Sieve VS LLR setup on here and would like the x64 PPS Sieve app please?

thanks :)
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