ONLY FOR RPI0/1 VERSIONS OF RECALBOX
Here is the binary for testing performance differences between fba and fba_libretro:
http://s000.tinyupload.com/index.php?file_id=01516935153730933111
(Re-)place the file inside usr/lib/libretro
Don't forget to make the partition rw before trying to copy it over:
mount -o remount,rw /
And share your results, please!