FFXI loads as a DLL so, tough luck D:
On my PC (it's a desktop) the other day I ran a GPU benchmark tool while FFXI was running and to my amusement I saw that the GPU was running on a very very low clock and the bus speed was set to PCIE 1.1 rates. Power saving at it's best.
I suppose that happens mostly because FFXI is CPU bound and that doesn't give the GPU enough encouragement to make it kick into high performance mode... >.>
I ran a "stress up" tab on the benchmarking tool and instantly FFXI became a little more smooth ... <.<
D'oh.
I can imagine this being a lot more of a serious issue on laptops where power savings are taken to extremes.