Instant boot faliure when setting ram to correct speed GA 990FXA UD3 R5

[bodleangus]

Hi, id like to know why my corsair vengeance ram underclocks itself to 1333 mHz and when I try to return it to 1600 mHz, i get a boot failure. It then resets it to 1333 mHz. The same happens when I try to edit my cpu frequency. This board was not bought brand new but it was bought second hand about a month ago and is no longer under warranty. The vengeance sticks are from different sets too. One is from a 3 stick set and one is from a single stick set. They are both similar and i dont know if that matters. I have tried re flashing the bios but no such luck in fixing anything. Any help is greatly appreciated. Thanks

 

[CountMike]

Give RAM some higher voltage, they can take it up to 1.65v or more.

 

[Calvin7]

"sticks are from different sets"

Such combinations have no guarantee to work together. Corsair and other memory manufacturers guarantee memory in the form sold and there are no guarantees for other combinations you happen to come up with.

Workarounds to get extra memory to work include:
Lower DRAM frequency
Increase DRAM voltage
Relax DRAM timings
Lower CPU multiplier

 

[bodleangus]

Thanks guys. Seems to work nicely at 1600.
It will oc to 1866 but instantly crashes the pc when booting into windows. But that doesn't bother me. Thanks heaps

 

[CountMike]

Which exact RAM ? My Kingston HyperX 1866 was working fine at that frequency.

 

[bodleangus]

It's corsair vengeance 1600mhz

 

[bodleangus]

Still having problems with random system hangs/ freezes. Could this be a mobo fault?