I have called Dukascopy support and get my answer, so i'll just share it here, for the sake of users that may search for way to speed up historical tester.
Gentleman with whose i was speaking, told me, that i should check how much CPU 'Jforex'[ = java process ] is using when 'historical tester' working. In my case, on one core 3 ghz with 4 gb ram, it was around 50-70%. Sometimes higher, but mostly around those values.
I was told than there is no sense at all with trying to run 'historical tester' on faster machine, because even my computer's power isn't fully used by testing, so faster machine will not make testing faster.
I've checked this theory in practise today.
I had a chance today to run 'Jforex' at E3-1230, 16GB DDR3, 100 mb/s server machine.
I can't swear that 'historical tester' was not even tiny faster on that pc, but the power of this computer is many times greater than the ones i'm using and 'historical tester' times of testing was almost the same, if not identical.
So - if You hope, like me, that faster processor, and more ram, and very fast internet will reduce testing time from an hour to 3 seconds, than i'm afraid, that You'll be dissapointed

I hope my post will spare someone time and unnecessary work.
Kind regards,
nine99