Problem memory 6GB recognize 2 or 4GB

[Moran]

I920 D0 no O.C
gigabyte ex58 ud3r bios F11
g.skill 6GB f3 15000cl9 2GB*3

the problem is that the memory isn't recognized as 6GB in post
it recognition depends on two things :

1- pure luck on turning the computer on(not restart only power shut)
sometimes it recognize as 6/4GB
2- when i try to turn the memory to 1866MHz its recognize it in Post as 2GB only
no matter what

Either way in win 7 its recognize always 6GB but write only 2\4GB Usable out of 6GB

the memory passed memtest with no error
i tried to change the memory slots no change
i checked the cpu for bended\broken he's o.k

thanks for the help
Moran

[Moran]

i didn't mentioned but sometimes it also working o.k as 6GB
OS 64 BIt

[GSKILL TECH]

Did you manually set the QPI/VTT Voltage? Find the lowest stable value to see if it will stabilize capacity as well.

Also, try each stick to see if one acts differently than the others.

Thank you
GSKILL TECH

[Moran]

i tried with QPI 1.3V and still dont work on 1866 its recognize only 2GB
on 1600MHZ its recognize 6\4GB and also not all the time

i will try one stick at a time
by the way QPI V of 1.3 is enough or to try more?

[GSKILL TECH]

Some i7 920 may need more QPI V, so try up to 1.50V.

If you continue to have the same problems, send the memory in for new replacements.

Thank you
GSKILL TECH

[Moran]

Ok after i tested each memory separately all three work fine on 1866MHZ speed
so connected all 3 sticks and it all worked fine for one hour and after i shut PC down and turned him on again he got started to work very very slow also after trying to loosen the MHZ to 1066 so i tried even one stick on all slots and got failed so now the PC got crazy and one BSOD but when checking on memtest he doesn't find errors does it can be the memory?

[Moran]

by the way now i working with 2 out of 3 sticks that only 2GB are usable

[GSKILL TECH]

If you'd like, send them in for new replacements to see if the new set works better.

Thank you
GSKILL TECH

[Moran]

Thanks for all the help

Moran

[Moran]

Hi i just received my new memory and everything working fine for now
i only had to set the memory for xmp profile 1 and all went ok for the first time
i wanted to say thanks for the help and for the great service!
thanks g.skill


by the way, small question, on the box of the new memory and web its written 1.6V and in bios its work at 1.65 why is that?

[GSKILL TECH]

XMP may be wrong, you can manually set it to 1.60V.

Thank you
GSKILL TECH

[Moran]

its seems to be 2 versions of the same model one is 1.65V and the other 1.6V
a link of 1 version : http://www.overclockers.ua/memory/gs...6000-15000.jpg

and another like in the website of g.skill to what i should i believe?

[GSKILL TECH]

Simply test it, if your chips can be stable at 1.60V, leave it so. The same model may have slightly varying specs throughout it's life span, so it simply depends on your particular set.

Thank you
GSKILL TECH

[Moran]

it's working fine on 1.6V
thanks for 1the great support