If you edit your posting and put code tags around them it will preserve the columns.
The obvious way of improving the performance is to make volumes
striped over the two disks assuming you can trash the current volumes and rebuild them, take a look at:
LVM HOWTO
As one of the two disks you mention has the operating system on it including swap (presumably), put the applications only on the other disk so that they are not competing with the OS for disk bandwidth.