Websor, are you sure it is windows that is spinning your drives down? I had no luck spinning my drives down with an intel sasuc8i and an m1015 flashed to lsi 9211 firmware.
The problem is the storport driver (which by default will not be supported by windows with power management features like spindown). It is possible to send spindown commands through sdparm or other programs, but windows will not use any of those.
So i think your driver is not a storport driver, or your saslp-mv8 has some settings about this.
At my setup, i made a batch file, which will set a timeout value after each start and let the drives handle the spindown.
There is only one problem. Windows will not know that and one sees pretty long access times because it (windows?
) has to wait for each drive (and will not start all at the same time).
If you are using xbmc or any other media player solution, thats no problem because there is only 1 access on that specific file.