The guy upstairs said that the crystal used for the South Bridge RTC clock is vibrating, and this one is also 32.768K.
In addition, the CLK GEN will use a 14.31818M crystal shock, and the network controller will use a 25M crystal shock.
The central clock chip mentioned by the main floor should refer to CLK GEN, what chip you can find from the motherboard, generally ICS, Realtek,winbond several companies.