well.. couldn't drop the vcore lower than 1.3

i've still got 10 days left of 30 days trade in thing, do you guys think i should try luck with other batch or stick with current?

current:

3847A839
191x21; 4011 MHz
HT on
1.3000 V in bios
1.264 V idle in windows
1.2000 under load

40 C temp idle (Titan Fenrir, fans 45%)
75 C under load with Linx

stable 50 linx passes

if i drop vcore just one lower, it fails linx after 20 seconds lol

mobo: ga ex58 ud5; f7 bios


would you say guys i should send it back and try the other batch, or this is just fine for 24/7 use and i should chill out?

also, what do you think about mobo? (i could get rampage II extreme for 75$ more)

thanx for replies =)