MPI-SpeedUp for SpinPack v2.33 (matrix at memory)
linear in plot: x=log(CPUs) y=log(t1/t)
lg2(t1/t) = b * lg2(CPUs) # t1 extrapolated 1CPU-time
t1/t = (2^(b))^lg2(CPUs) # 2^b = SpeedUP2 (CPU-doubling)
t1/t2 = (2^(b))^lg2(2) = 2^b = SpeedUp2
BWFactor = (t1/t(1CPU)) # Band Width Factor
OverallSpeedUp = SMPSpeedUP * MPISpeedUp
SMPSpeedUp = SMPSpeedUp2 ^ lg2(SMPCores)
MPISpeedUp = BWFactor * MPISpeedUp2 ^ lg2(MPINodes)
SpeedUp2 SMP = 1.66 (up to 32 CPUs), MPI = 1.46 (up to 64 nodes)
BWFactor 100Mbit/s = ca. 40% ( 40% float, 25% double, 2*2GHz)
1Gbit/s = ca. 100% (100% float, 70% double, 4*2Ghz)
2*10Gbit/s = ca. 100% (estimated, BW*Cores/Node)
extrapolation:
SpeedUp = 1.66^lg2(SMPCores) * 1.46^lg2(MPINodes)