Drop the sfz into Notepad and you will see:

<global>


<control>
hint_ram_based=0

<group>


So it will load the required wma files into ram if:
hint_ram_based=1

it will play the files direct if:
hint_ram_based=0

there are 2 sfz, one will play from ram and one will play from hard drive.

Quote:
hint_*

Its a 'hint' to the ARIA engine, others implementations don't have to follow.

ARIA supports specific opcodes in ‹control› which start with “hint”, these should be ignored by any other SFZ parser. Other engines could implement other hints as they wished.

A useful case is hint_ram_based=1, which will cause the samples to be loaded into RAM in their entirety, instead of preloading only starts into RAM and streaming the rest from disk. This can be useful for preventing sound dropout with larger instruments on lower-performance systems, or instruments located on a HDD.