Important Change to NIH Biowulf -- "e2666" properties changed (Biowulf)

A configuration change to the 8-core, 2.666 GHz, 24 GB nodes has 
allowed these nodes to support 16 threads-of-execution. Previously 
these nodes could be specified by using the c8 property. Effective 
immediately, two changes will be made to the PBS batch properties 
used to select for these nodes:

-- The c8 property will be replaced with the c16 property reflecting 
the fact that these nodes can now support up to 16 processes or 
threads-of-execution. The swarm command will automatically place 16 
processes on these nodes (see below for performance implications). 
Jobs allocating c16 nodes will only be "charged" for 8 cores against 
the cores per user maximum. This effectively doubles your core limit 
when running on c16 nodes.

-- The m2 (gigabytes of memory per core) property for these nodes will 
be replaced by m1 reflecting the change in the "core" to memory ratio.

The c8 property will continue to be valid for 60 days; after that, 
specifying this property will result in an error. The g24 or g72 
(gigabytes of memory per node) properties will not change for these 
nodes.

Performance

The Biowulf staff have run numerous application benchmarks on the 
e2666 nodes using 16 processes/threads-of-execution with the 
following _generalized_ results:

-- Multi-threaded programs such as `cufflinks' will generally see an 
improvement in performance when running 12 or 16 threads over 8.

-- Running greater than 8 processes such as `R' can result in higher 
throughput at the cost of somewhat longer job walltime.