In Computer Science Helman-Bader-JaJa model is a concise message passing model of parallel computation defined with the following parameters:
p
is number of processors.
n
is the problem size.
m
is number of machine words in a packet sent over the network.
τ
is the latency, or time at which a processor takes to initiate a communication on a network.
σ
is the bandwidth, or time per machine word at which a processor can inject or receive
m
machine words from the network.
T
c
o
m
p
is the largest computation time expended on a processor.
T
c
o
m
m
is the time spent in communication on the network.
This model assumes that for any subset of
q
processors, a block permutation among the
q
processors takes
(
τ
+
σ
m
)
time, where
m
is the size of the largest block.
