Samsung H61s1 Manual __full__ -
jumper or removing the CMOS battery for 30 seconds while the power is unplugged. Power Connectors : Ensure both the 24-pin ATX main power and the 4-pin (or 8-pin) CPU
The manual emphasizes:
1 x PCI Express 3.0/2.0 x16 slot for dedicated graphics cards. samsung h61s1 manual