This is what i sent to Gigabyte support on 10/28/2011. No reply yet.
CPU: i5-2500k
Mobo: Gigabyte GA-Z68X-UD3H-B3
Ram: G.Skill F3-12800CL9D-8GBXL 2x4gb ddr3 1600
PSU: Cooler Master RS700-PCAAE3-US 700W
Vid: Galaxy 56NGH6HS4IXZ GeForce GTX 560 Ti
HDD: Samsung Spinpoint F3 1 TB
Optical: ASUS DRW-24B1ST/BLK/B/AS
Case: CM Storm Scout
BIOS: F10
This is a new build. When I have to sticks of ram I must downclock the ram frequency to 1066mhz. Anything higher and the system will go into a boot loop without even posting. I can have 1 stick of Ram in at 1333mhz or 1600mhz but when I put 2 sticks in the frequency must be 1066mhz or lower. I have tried this with 2 types of ram with the same results. 1) Patriot Viper Xtreme Series, Division 2 Edition 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model PXD38G1600LLK 8-9-8-24 1.65v. 2)G.SKILL Ripjaws X Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-8GBXL 9-9-9-24 1.5v. I have tried using XMP settings, automatic settings, and manually setting the frequency and timings to the ram's specifications and the motherboards. Every time it was the same story. 1 sticked worked. 2 sticks had to be at 1066.When I went from 2 sticks to 1 after not posting and going into boot loop it would say the motherboard has recovered from an overvoltage/overclocking error values may not be accurately defined. Also, I can only put the one stick in the 4 slot. Any others and I have to follow the same rules when using 2 sticks, downclock to 1066 or lower. Please help me fix this or is this just a bad board?