Thanks for the answer,
In the BIOS of the P4, I activated the following settings :
IDE Primary Master PIO [auto] -> I can change to : auto,mode0,mode1,mode2,mode3,mode4
IDE Primary Slave PIO [auto] -> I can change to : auto,mode0,mode1,mode2,mode3,mode4
IDE Primary Master UDMA [auto] -> I can change to : disabled,enabled
IDE Primary Slave UDMA [auto] -> I can change to : disabled,enabled
I tryed to change the PIO setting to mode0, mode1, mode4, but at the startup I always see : LBA, ATA 100,.. never UDMA.... I can't really disabled PIO !
How to force UDMA ?
thanks
twister