with the new bootloader you may change now the cpu clock setting up to 800 mhz.
just set the uboot env var "cpu_clock" and reboot. if this var is not set, the default cpu clock will be used
which is 600 mhz for a standard gw2388. this might also work for gw2380, but its not tested

example:
env set cpu_clock 800
reset

valid values are :
300
333
366
400
433
466
500
533
566
600
633
666
700
733
766
800