Soapman72 Thx but Answer at all this question please , I am french and not sure if I understang 100% correcly.

1)You tell Corsair recommend 1.71V this is right, but Do you tell Asus tell is safe for 24/7 use ?

2)when you put 1.71 the board is under is warrantly or not ?

3)Can do you put the link of the place you have see a personnal from Corsair tell what you have write ?

4)And Soapman72 , if you have read my message, you have understang that , if I put more then 1.55V I am more unstable then 1.55.I have try 1.57 1.59 1.61 1.63 and 1.65 all with a Fan on NB a 119CFM fan.It not normale to have more instabillity when I put more voltage.

Exemple

success run 435FSB CPU 3490MHz Ram 1741(under below spec)

If I put 1.51volt to NB 13 minute stable of Prime 95
If I put 1.53 volt to NB 54 minute stable of Prime 95
If I put 1.55 volt to NB 9 minute stable of prime 95
If I put 1.57 volt to NB 3 minute stable of Prime 95 ...