What can cause a mobile Barton 2600+ to run Prime95 stable at 210x11.5 with 1.76 VCore on one NF7-S 2.0 motherboard and need 1.84 VCore to be Prime95 stable at 208x11.5 on a different NF7-S 2.0 motherboard?
<font color=red><b>NF7-S/MBarton 2500+
210x11.5 1.82v SP-97
1GB Corsair XMS PC3200
BBA 9800 Pro 423/369</font color=red><font color=black>
NF7-S/MBarton 2600+
210x11.5 1.76v
512MB CVR PC3200
Sapphire 9500@9700
<font color=red><b>NF7-S/MBarton 2500+
210x11.5 1.82v SP-97
1GB Corsair XMS PC3200
BBA 9800 Pro 423/369</font color=red><font color=black>
NF7-S/MBarton 2600+
210x11.5 1.76v
512MB CVR PC3200
Sapphire 9500@9700