type CMD into Start Search box, rightclick to run as Admin, type "Diskpart," , then "list disk"
If all disks are the same size and are fully occupied with partitions, you will not be able to tell them apart because the free space will always be shown as zero. For that you have to use a little trick. Shrink a few MBs off a partition on each drive and leave it as unallocated space. If you use a different number of MBs per drive, you will be able to tell them apart because those shrunk MBs will show as free space. Example Disk1:
DISKPART> list disk
Disk ### Status Size Free
-------- ---------- ------- -------
Disk 0 Online 233 GB 0 B
Disk 1 Online 233 GB 1199 MB
Disk 2 Online 15 GB 0 B
Now you know which port serves which disk.