Communication Is Important
•So far
the algorithm is “send-then-compute”
•Try
overlapping and computing
•Use
broadcast communication
B
C
Pa
Pb
Pe
Pf
Pi
Pj
Pm
Pn
Pc
Pd
Pg
Ph
Pk
Pl
Po
Pp
Pa
Pb
Pe
Pf
Pi
Pj
Pm
Pn
Pc
Pd
Pg
Ph
Pk
Pl
Po
Pp
+
x
1
1
x
2
2
x
3
3
x
k
k
+
+...
=
A
Pa
Pb
Pe
Pf
Pi
Pj
Pm
Pn
Pc
Pd
Pg
Ph
Pk
Pl
Po
Pp
