extra memory gives me code 15

[edin__]

I have a gigabyte ud5h mobo and i wanted to add some extra memory to my 2x4 that i have installed already. But when i add the extra 2x4 and try to start the PC, it gives me code 15 and restarts again and it keeps doing it. I tested the new memory as-well and boots up just fine. I just cant seem to get the full set to work property

Thanks for your input

i also cleared the cmos, but no luck and yes they memory is the same brand/model but the version on the sticks differ, 1 is version3.24 and other is version2.22

 

[Dark Lord of Tech]

Mixing and matching memory is hit and miss , even identical modules purchased at different times can be incompatible.