Re: [tlug] SATA software RAID or SAS hardware RAID?

["Stephen J. Turnbull" <turnbull@example.com>]

Edward Middleton writes:

 > If you are only running on a single machine why are you using PVM?

If you are reproducing footnote 1, why aren't you reading it? ;-)

 > > [1]  Using the PVM package, which probably communicates via TCP/IP
 > > over Unix-domain sockets.  MPIv2, several implementations of which
 > > have good shared memory support, seems to be the way to go for real
 > > work, but PVM comes with "batteries included" for demos, eg, a nice
 > > XPVM visual monitor, and extending to heterogenous networked VMs is
 > > trivial.

 > Perhaps it is not optimized for parallel processing on a single machine.

Well, sure---communicating via sockets is not the way to go on a
single machine if you have greed for speed.  Point is, "requires
optimization" is what I meant by "non-trivial".  And the 1000-to-1
degradation in performance is pretty spectacular considering that in
the end doing all the communication requires only copying about 2000
small (< 500 bytes) buffers.