Ram problems

[Foxjk013]

Hey guys first time posting…
Currently I am using a GA-78LMT-USB3 mobo but for some reason i keep getting ram error when installing ram over 16GB but with looking on the gigabyte website it says the mobo accepts up to 32GB. I am thinking it was my processor at the time just want to double check. What am I doing wrong?
My rig is....
Windows 8 64bit
My processor I tried the memory with was AMD Anthlon x2 270
New processor I got yesterday is the
AMD fx-6300
Old gpu was a
xfx Radeon HD 7770 ghost thermal
New gpu installed yesterday is a
Nvidia gtx 750 ti
Mobo is
GA-78LMT-USB3 (Rev 4.1) f4
Current memory is 16GB (4x4GB)
Please note I haven't tested the memory upgrade with the new CPU and GPU yet. And will this setup bottleneck my system?

[autotech]

your motherboard will be the bottleneck in your system.

[Foxjk013]

i found this motherboard MSI 970 GAMING AMD 970 (SOCKET AM3+) DDR3 ATX MOTHERBOARD. Any suggestions on this?