Server mainboard based on non-standard PCIE spacing

The utility model provides a server mainboard based on nonstandard PCIE spacing, including: reference mounting hole, circuit mainboard, first interface module, second interface module, third interface module and PCIE module, the reference mounting hole is provided in the corner of the circuit mainboard, the PCIE module is provided in the side of the circuit mainboard close to the reference mounting hole, the second interface module is provided in the side of the circuit mainboard close to the first interface module, and the third interface module is provided in the side of the circuit mainboard close to the second interface module. The first interface module, the second interface module and the third interface module are sequentially arranged on the side, away from the reference mounting hole, of the circuit mainboard side by side, and the distance between the vertical center axis of a PCIE mounting groove in the PCIE module and the vertical center axis of the reference mounting hole ranges from 4.11 mm to 18