I Strategia
MIMD-DM MIMD-SM
T(1) = M(2N - 1)tcalc
T(p) = M/p (2N - 1)tcalc
S(p) = T(1)/T(p) = M(2N - 1)tcalc/M/p (2N - 1)tcalc = p tcalc/M(2N - 1) = p
Oh = pT(p) - T(1) = p M/p (2N - 1)tcalc - M(2N - 1)tcalc = 0
E(p) = S(p)/p = p/p = 1
I Strategia
MIMD-DM MIMD-SM
T(1) = M(2N - 1)tcalc
T(p) = M⁄p (2N - 1)tcalc
S(p) = T(1)⁄T(p) = M(2N - 1)tcalc⁄M⁄p (2N - 1)tcalc = p(2N - 1)⁄M(2N - 1) = p
Oh = pT(p) - T(1) = pM⁄p (2N - 1)tcalc - M(2N - 1)tcalc = 0
E(p) = S(p)⁄p = p⁄p = 1
I Strategia con W-A
Posto T(1) = 1, Ts = α e Tc = (1 - α), il tempo T(p) diventa
T(p) = Ts + Tc⁄p = α + 1 - α⁄p = 0 + 1 - α⁄p = 1⁄p
Anche lo speed up calcolato con la legge di Ware è pari a p
S(p) = T(1)⁄T(p) = 1⁄1⁄p = p
II Strategia
Metodo Somma I
MIMD-SM
T(p) M(2N/p - 1)tcalc + M(p - 1)tcalc = (2N/p - 2 + p)Mtcalc S(p) M(2N-1)/M(2N/p-2+p) = 2N-1/2N/p-2+p Oh(p) pM(2N/p - 2 + p) - M(2N - 1) E(p) 2N-1/2N/p-2+p1MIMD-DM
T(p) M(2N/p - 1)tcalc + M(p - 1)tcalc + M(p - 1)tcom = M(2N/p + 3p - 4)tcalc S(p) M(2N-1)/M(2N/p+3p-4) = 2N-1/2N/p+3p-4 Oh(p) pM(2N/p + 3p - 4) - M(2N - 1) E(p) 2N-1/2N/p+3p-41 OC M(p-1)tcom/M(2N)/p)+M(p-1)tcalc = 2(p-1)/2N+p-2II Strategia
Metodo Somma II e III
MIMD-SM
T(p) M\left(\frac{2^N}{p}-1\right)t_{calc} + M\log_2(p)t_{calc} = M\left(\frac{2^N}{p}-1+\log_2(p)\right)t_{calc} S(p) \frac{M(2N-1)}{M\left(\frac{2^N}{p}-1+\log_2(p)\right)} = \frac{2^N-1}{\frac{2^N}{p}-1+\log_2(p)} Oh(p) pM\left(\frac{2^N}{p}-1+\log_2(p)\right) - M(2N-1) E(p) \frac{2^N-1}{\frac{2^N}{p}-1+\log_2(p)} pMIMD-DM
T(p) M\left(\frac{2^N}{p}-1\right)t_{calc}+M\log_2(p)t_{calc}+M\log_2(p)t_{com}=M\left(\frac{2^N}{p}-1+3\log_2(p)\right)t_{calc} S(p) \frac{M(2N-1)}{M\left(\frac{2^N}{p}-1+3\log_2(p)\right)} = \frac{2^N-1}{\frac{2^N}{p}-1+3\log_2(p)} Oh(p) pM\left(\frac{2^N}{p}-1+3\log_2(p)\right) - M(2N-1) E(p) \frac{2^N-1}{\frac{2^N}{p}-1+3\log_2(p)} p OC \frac{M\log_2(p)t_{com}}{M\left(\frac{2^N}{p}-1\right)t_{calc}+M\log_2(p)t_{calc}} = \frac{2\log_2 p}{\frac{2^N}{p}-1+\log_2(p)}Il Strategia con W-A
Metodo Somma I
α = M(p-1)⁄M(2N-1) = p-1⁄2N-1
1-α⁄p = M(2N⁄p-1)⁄M(2N-1) = 2N⁄p-1)⁄(2N-1)
T(1) = M(2N-1) = α + 1-α⁄p = 1
T(p) = α + 1-α⁄p
S(p) = T(1)⁄T(p) = 1⁄p-1⁄2N-1 + 2N⁄p-1⁄2N-1
= 1⁄p-1+2N⁄p-1⁄2N-1
= 2N-1⁄p-1 + 2N⁄p-1
Il Strategia con W-A
Metodo Somma II e III
α1 = M / (M(2N − 1)) = 1 / (2N − 1)
αp = [pM(2N / p − 1)] / (M(2N − 1)) = [p(2N / p − 1)] / (2N − 1)
α2log2 p−k = [M2log2 p−k] / (M(2N − 1)) = [2log2 p−k] / (2N − 1)
T(1) = M(2N − 1) = α1 + Σk=1 [ (α2log2 p−k / 2log2 p−k) ] + [ αp / p ]
T(p) = α1 + Σk=1 [ (α2log2 p−k / 2log2 p−k) ] + [ αp / p ]
S(p) = 1 / [ α1 + Σk=1log2 p−1 [ (α2log2 p−k / 2log2 p−k) ] + (αp / p) ] = (2N − 1) / [ log2 p + 2N / p − 1 ]
III Strategia
Metodo Somma I
MIMD-SM
T(px, py)M⁄px(2N⁄py - 1)tcalc + (py - 1)M⁄pxtcalc = (2N⁄py - 2 + py)M⁄pxtcalcS(px, py)M(2N - 1)(2N - 1)⁄px(2N⁄py - 2 + py)Oh(px, py)pxpy(2N⁄py - 2 + py)M⁄px - M(2N - 1) = Mpy(2N⁄py - 2 + py) - 2N + 1E(px, py)(2N⁄py - 2 + pyM⁄px - M(2N - 1) = (2N⁄py - 2 + py)- 2 + pxpyMIMD-DM
T(px, py)M⁄px(2N⁄py - 1)tcalc + (py - 1)M⁄pxtcom = (2N⁄py + 3py - 4)M⁄pxtcalcS(px, py)M(2N - 1)(2N - 1)⁄px(2N⁄py + 3py - 4)Oh(px, py)pxpy(2N⁄py + 3py - 4)M⁄px - M(2N - 1) = Mpy(2N⁄py + 3py - 4) - 2N + 1E(px, py)(2N⁄py + 3py - 4)pxpyM⁄pxOC(py - 1)M⁄pxtcom = 2(py - 1)py⁄pxtcalcIII Strategia
Metodo Somma II e III
MIMD-SM
T(pxpy) M / px (2N / py - 1) tcalc + log2py M / px tcalc = (2N / py - 1 + log2py) M / px tcalc S(pxpy) M(2N - 1) / (2N / py - 1 + log2py) M / px = 2N / py - 1 + log2py Oh(pxpy) pxpy (2N / py - 1 + log2py py - M(2N - 1) = M / py (2N / py - 1 + log2py) - 2N + 1 E(pxpy) (2N - 1)px / (2N / py - 1 + log2py M) / px = (2N / py - 1 - 1 / py = 1)MIMD-DM
T(pxpy) M / px (2N / py - 1) tcalc + log2py tcom + log2py M / px tcalc = (2N / py - 1 + 3log2py) M / px tcalc S(pxpy) M(2N - 1) / (2N / py - 1 + 3log2py) M / px = 2N / py - 1 + 3log2py Oh(pxpy) pxpy (2N / py - 1 + 3log2py py - M(2N - 1) = M / py (2N / py - 1 + 3log2py) - 2N + 1 E(pxpy) (2N - 1)px / (2N / py - 1 + 3log2py M) / px = (2N / py - 1 - 1 / py = 1) OC M / px (2N / py - 1) tcalc + log2py M / px tcom + log2py M / px tcalc = 2log2 pyIII Strategia con W-A
Metodo Somma I
αpxpy = pxpy M/px (2N/py - 1) 1/M(2N-1) = py (2N/py - 1) 1/2N-1
αpx = px(py - 1) M/px 1/M(2N-1) = (py - 1) 1/2N-1
T(1) = M(2N-1) = αpxpy/pxpy + αpx/αpx
T(p) = αpxpy/pxpy + αpx/αpx
S(p) = 1/αpxpy/pxpy + αpx/px = (2N-1)px/2N/py - 2 + py
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Appunti di Calcolo Parallelo e Distribuito
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Domande e risposte esame Calcolo parallelo
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Calcolo
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Calcolo numerico - riassunti, formulario