Discussion related to cado-nfs

[paul zimmermann <Paul.Zimmermann@inria.fr>]

       Rob,

> Using bridged networking and 8 MIC co-processors, hybrid Xeon and Xeon
> Phi execution is feasible.  Ten factor trials of RSA-120 finished in
> under 2 hours.
> (1.6337+1.6400+1.6357+1.7245+1.6255+1.7062+1.6105+1.6214+1.6021+1.6321)/10=1.64317
> hrs

I've just added timings on http://cado-nfs.gforge.inria.fr/ with 2.2.0:
on a dual 8-core Intel(R) Xeon(R) CPU E5-2650 at 2.00GHz, factoring
RSA-120 with CADO-NFS 2.2.0 takes about 2.2 hours of wall clock time
(32.2 hours of cpu time). You used about 1200 hours cpu.

> 1.) Will MPI enable utilization of the 1920 MIC cores for linalg?

I let Emmanuel answer to that.

> 2.) Will MPI enable utilization of the 1920 MIC cores for sqrt?

there is no need. The square root step takes negligible time.

> 3.) Will MIC offloading enable utilization of the 1920 MIC cores for linalg?
> 4.) Will MIC offloading enable utilization of the 1920 MIC cores for sqrt?
> 5.) Considering future-proof development, should efforts focus on MIC
> offloading or MPI?

I'm not sure this make sense, given the relative slowness of the MIC cores
(1200 cpu hours for RSA-120 instead of 32 cpu hours).

Paul