Motherboard not allowing 1600MHz RAM to boot

grandmst20

Prominent
Feb 24, 2017
13
0
510
AMD FX-9590 @ 4.7GHz (Stock)
Corsair H100i v2
32.0GB Dual-Channel Corsair CMY16GX3M2A1600C9 DDR3 @ 669MHz (9-9-9-24)
Gigabyte 990FXA-UD3 R5
EVGA NVIDIA GeForce GTX 1070 FTW Edition
Mushkin MKNSSDEC512GB (OS)
Western Digital WDC WD20EURX-57T0FY0
Seagate Barracuda ST2000DM006-2DM164
Corsair RM850 PSU
Windows 10 Pro 64-bit

Anytime I change the BIOS settings from 1333 to 1600 it'll fail to boot and ask me to revert back or change settings. My previous motherboard (Asus M5A97 LE R2.0) ran the memory at 1600MHz just fine. I contacted Gigabyte about the issue and they said it's not supported by the motherboard model I have. After checking the support documentation on their website it seems as if very many memory modules (minus mine) are supported.

I just wanted to double check and see if Gigabyte customer service was taking the easy route of saying "no."