System only reading half of RAM

[TargusBaoRa]

I'm having a RAM issue with a computer running a Gigabyte GA-MA780g-ud3h motherboard and an AMD Phenom II X4 810 CPU. I have a pair of 4 GB modules installed in the proper slots, totaling 8 GB, but the system only recognizes that 4 gigs are present. At first I thought I had a dead module, but when I took one out to test this, the system loaded recognizing only 2 GB of memory instead of 4. I checked this in the BIOS/CMOS as well and it also read 2 GB. I can't figure out why only half the memory in place is being read. The MOBO is supposed to support 16 GB total so it only makes sense that it should be able to recognize 4 GB modules. Could this be a compatibility issue with the processor? Or something in the BIOS I'm overlooking?

 

[Tradesman1]

What set of DRAM do you have, the actual model #

 

[Zaoldyeck216]

First of, make sure your OS supports 4GB+ of Ram. Windows 64bit.
Check you motherboards manual and check how the dual slot works. Sometimes it has to be put in a specific slot for it to work.
EX: slot 1&3 then 2&4 / 1&2 then 3&4 etc etc...
Also, try switching out the Rams and see if they work by themselves.
Good luck!

 

[TargusBaoRa]

What set of DRAM do you have, the actual model #

False Alarm :
As I was reading off the model number I noticed something underneath it :
Right after the speed specification, in small print it says 2GB x2
Apparently these are really 2 GB sticks, but the model number reads as such
F2-6400CL4D-4GBHK
This lead me to believe they were 4 GB each, but I guess the model number and label refer to the packaging for the product containing 4 GB total. I'm used to the model number referring to the actual module, not the packaging, so I assumed each stick was 4 GB and overlooked the line below where it said 2GBx2.
Well, that's embarrassing, but I'm working on a friend's computer that I don't have all the background info on, so I guess these things happen. Your advice did lead me to the answer in an unexpected way, so thanks, and sorry for the false alarm. I'll be more attentive to labels and packaging in the future

 

[Tradesman1]

No problem, those are the GSkill HK sticks, been around awile and are great sticks, which is why I asked for model number, a lot of people don't read the mocel number correctly and think as you did it's each stick