Why can't he see the bar of RAM?

Question

Windows

Computer yesterday, just bought.
Mother - ASUS M5A78L-M / USB 3.0
Two sticks of RAM - one Kingston DDR3 4GB, PC3-12800, 1600 MHz, KVR16N11S8 / 4, the second - Qume DDR3 4Gb, PC10666, 1333 MHz
OS Win 7 64x
When I insert two at once - only 255 MB of memory , I put only the second - the same thing. When there is one first - everything is fine, 4 GB costs. I just bought the second one today. What could be the reason?
UPD: now even when I put the first bar - exactly the same 255MB

Answer 1

255 mb where do you see it? Maybe it's a seer?
The memory should show either 4 or 8 or the computer should not start at all.
In theory, if you set two bars, both should work for you at the slowest speed (1333).
Check your BIOS to see if you have a hard-coded frequency somewhere, if so, set everything to auto, or set all timings to start the slowest bar.

Answer 2

It is not advisable to insert strips from different manufacturers into dual-channel mode. You even have a different class of brackets (PC3-12800, 1600 MHz and PC10666, 1333 MHz).
In a good way, both slats should be from the same package. Or one model. And in your case, I advise you to find another Kingston DDR3 4GB, PC3-12800, 1600 MHz, KVR16N11S8/4 bar.

Answer 3

reset the bios to default and then see how much RAM the mother sees