maybe your p45 dont have it.i know my ST needed tRC set manually or it would set 20 or 21 instead of the SPD of 37

Channel A & B

Channel A Timing Settings [Press Enter]:
Cas Latency Time........................[10]
tRCD....................................[10]
tRP.....................................[10]
tRAS...................................[24]

>>>>> Advanced Timing Control

tRC....................................[37] this is it on my bios
tRRD...................................[4]
tWTR...................................[5]
tWR....................................[10]
tWTP...................................[22]
tWL....................................[8]
tRFC...................................[74]
tRTP...................................[5]
tFAW...................................[20]
Command Rate (CMD)......................[ 1T ]
Static tRD......................................[12]