From the jetway site:
JETWAY Mother Board Can Support 5.5X / 6.0X / 6.5X /7.0X CPU Ratio , But Old Manual no Show it , Please Contact to CPU Ratio Selector Adjust it

CPU Ratio Selector Include : J-7XA/J-7XB/J-7XCS/J-7XAS/J-7XAN/J-7BXA/J-7BXAR2 /J-7BXAS/J-7BXAN/J-7ZXAS/J-7ZXAN/J-756BF/J-791A /J-791AR2/J-791BS/J-791BN/ J-791BSR2/J-791BNR2/J-7LXAR2 Mother Board

CPU Ratio selector (second row from bottom for J-7XA):
http://www.jetway.com.tw/evisn/faq/jump.html