If you look into Wikipedia and search for DVI, you might find this Pic.
There it shows:
DVI-I single and dual (those ones with the 4 pins on ground[big pin])
DVI-D Single and dual (those without 4pins on ground[big pin], groundpin is also smaller)
If you have a DVI-D cable with 8x3 small pins, then its dual (the one you need).
Just to make sure you understand what I ment: You need
one DVI-D (dual link) cable.
Not 2 cables and
no additionally adapters.
Monitor-sLot: DVI-D (dual link slot) +
Cable-pins: DVI-D (dual link pins) +
VGA-slot: DVI-I (dual link slot) = OK
Any other cable won't work.
Or You by one of these
adapters for your already existing DVI-I (dual link) cable, which nearly costs the same as the
cable....