This is what I wrote to Ghislaing:
On the old Bestec psu which I believe is a 250 watt, this is the configuration: The P3 connnector is a 1X4 pin. 2 yellows,4 blacks,2 reds. It is part of the cluster that has P2,P3, & P8. P2 & P3 are both 1X4 pins & P8 is a small connector with 4 pins.
Then there is a cluster that has P4,P5 & P6. P4 & P5 are both 14 PINS P6 is a very small connector with 4 pins. The third big connector is the main connector to the MOBO. It has 20 pins. There is a P7 connector which is 4 pin with only yellow & black wires.
My new psu unit has a big connector with 20 pins and there is also a small 4 pin connector with it, which I believe plugs into the MOBO as the new psu is is a 400 watt