Boot emuelec is slow,Help

Hi ,Geekers!My S905m box boot by hdd 、usb drive、ssd slow than sdcard,I try edit “aml_autoscript” :

setenv upgrade_step 2
setenv usbdtb ‘if fatload usb 0 ${dtb_mem_addr} dtb.img; then else store dtb read $dtb_mem_addr; fi’
setenv bootfromusb ‘usb start 0; if fatload usb 0 ${loadaddr} kernel.img; then run usbdtb; setenv bootargs ${bootargs} bootfromusb; bootm; fi’
setenv bootcmd run bootfromusb; fi; run storeboot’
saveenv
run storeargs
run bootfromusb

but it may not work,all usb device seem boot slower than sd card;the hdd boot process is thant : loading sometimes,and pause above 30 sec,then contionue loading emuelec normally。

So Is there some way to reslove it;thank you every much!!!

Answered here for future reference:

I got it, q5 box slow;900v22d box is fast by usb boot。