Use the Auslogics Disk Defragmenter instead.
Power Defragmenter isn't really good, as it might leave fragmented areas left behind if your disk is too full (And it doesn't warn you about them).
There should not even be a little part of your game files being fragmented - so there should be not even be one red square (Fragmented region) shown on the graphical representation of your disk by your disk defragmentation utility.
You might want to try PS2ESDL instead, since that it's geared towards the use of USB devices (Whereas OPL is not) and might solve some issues related to slow USB device data transfers.
FFXII seems to work better on OPL though (Less stuttering, and no need to enable the "Force Synchronization" mode of PS2ESDL).
Unmodified SCPH-77006 with SM 3.6
SCPH-39006 with M-chip modchip, SCPH-10281 NA and refurb Seagate 80GB HDD
SCPH-10000 v1.00 with SCPH-10190 PCMCIA NA and SCPH-20400 HDD unit