# Question:Maple 2015.0 : comparisons of cpu time between Windows 7 and XP machines

## Question:Maple 2015.0 : comparisons of cpu time between Windows 7 and XP machines

Maple 2015

Hi everybody,

Until recently I was using Maple 2015.0 on this PC :

Windows XP
2 dual core proc Intel(R) Xeon(R) CPU E3-1225 V2 ; 3.19 GHz
64 bytes,
16 Go RAM

For two days now I am using Maple 2015.0 on this one

Windows 7
4 dual core proc Intel(R) Xeon(R) CPU 5-2637 V3 ; 3.50 GHz
64 bytes,
64 Go RAM

Comparisons of the running times for exactly the same code, consisting in 10000 independent Monte Carlo  simulations distributed over all the nodes (resp 4 and 8) give :

Windows XP :  504 sec  (with a variation of the order of  +/- 3s for different replicates)

Windows 7   :  343 sec  (with a variation of the order of  +/- 3s for different replicates)

The expected running time should be 504 * (3.2/3.5) * (4/8) = 230 s
(or 504 * (4/8) = 252 s if you neglect the acceleration due to the clock rate)
The realized running time (343 s) is thus at least  40% larger than the expected one.

Does anybody has already observed this kind of performance loss during XP -> 7 migration ?
Are there some comparisons of cpu times between Windows XP and 7 ?

Thank you all for sharing your own experience.

postscript : a NOTIONALexample of how the computations are distributed is given below

NbOfRuns := 10000:

# Data is a Matix(NbOfRuns, NbOfCols, …) constructed elsewhere

NbOfNodes := Grid:-NumNodes():
NbOfRunsPerNode := NbOfRuns / NbOfNodes:
for k from 0 to NbOfNodes do
FirstData := 1 + k * NbOfRunsPerNode:
LastData := (k+1) * NbOfRunsPerNode:
Grid:-Run(k+1, MyCode, [Data[FirstData..LastData, ..], …])
end do:

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