Hello,

On page:

http://localhost/glucas/doc/Configure-Make-and-Install.html#Configure%20Make%20and%20Install

you will see the multithread options you can use at './configure' time. You 
can use Sunmp (for Sun compilers), Openmp (for compilers supporting that) and 
POSIX threads.

The doc about the internals of how the work in a L-L test iteration is 
splitted is unclear and not updated.  I must rewrite that.

I'm sure that multithread code is not optimal, it not scale well for many 
processors. Its improvement will require a more carefull tunning work. It was 
hard to me the wrote the code with limited access to some systems (mainly HP 
test-drive site)  from a Linux-PC box. 

The most severe bugs were found and fixed with the work and valuable help from 
Tony Reix and Jeff Gilchrist when verifying M41 and M42.

Guillermo.

El S�bado, 2 de Abril de 2005 04:47, Greg Edwards escribi�:
> I think I have misunderstood the references to "multi-processor" L-L tests.
> Dr Nowak's M42 was found in 50 days on his 2.4GHz P4, and verified in 5
> days on an Itanium 16p machine, but it looks like the Itanium app was
> single-threaded. I have searched all of http://www.oxixares.com/glucas
> <http://www.oxixares.com/glucas>   and found no refernece to parallel
> options.
> As mentioned many times in this forum and the Gimps pages, the L-L test is
> a consecutive linear algorithm, you can't cut it into parallel pieces. The
> 50/5 ratio above is only about what one would expect from the P4/IA64 chips
> and associated 8x cache size improvement etc, esp. as Glucas apparently
> exploits an IA64 instruction set feature which doubles the performance of
> L-L.
> So it looks like I can't offer to verify M43 in a few minutes on a 512p
> IA64 after all.
> Greg E
>
> Greg Edwards
> Technical Consultant
> SGI
> 11-17 Khartoum Road
> North Ryde NSW 2113 Australia
> Ph: +61 (0)2 8875 9580 (diverts to mobile)
> Fx: +61 (0)2 8875 9480

-- 
Guillermo Ballester Valor
[EMAIL PROTECTED]
Ogijares, Granada  SPAIN
Linux user #117181. See http://counter.li.org/
Public GPG KEY http://www.oxixares.com/~gbv/pubgpg.html

 
_______________________________________________
Prime mailing list
[email protected]
http://hogranch.com/mailman/listinfo/prime

Reply via email to