Two on the PATA ribbon cable. Two via the two SATA connectors.
A total of four devices. You paid $49 for a motherboard, and
you got capability for four devices total.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131223
For $90, this one has two PATA (on one ribbon cable) and six SATA.
The extra $40 buys you four more SATA ports.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131273
For $180, this one has two PATA, six SATA (Southbridge), two SATA
(on a separate SIL3132 controller).
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131011
And you can always buy an add-in card with more storage
interfaces, if you want to. For $20, you can get two
extra SATA ports. This card is from Syba and uses a
SIL3132 PCI Express x1 chip to make the two ports.
(This would only work if you have the M2V-MX SE, as it
has a PCI Express x1 slot. You can plug this into the
PCI Express x16 slot, but that would be a terrible waste
of a video card slot.)
http://c1.neweggimages.com/NeweggImage/productimage/15-124-027-06.jpg
If you connect one of these boxes to the SIL3132, it converts one
SIL3132 port into five ports. Using two of these boxes
(the boxes are $100 each), you could control up to ten disks
from the SIL3132 chip.
http://www.sataport.com/
And you can always use a USB2 to SATA or USB2 to IDE adapter,
and connect disks that way (external enclosures or the bare
adapter cable products).
Paul