Did you buy those 8GB sticks as a kit or two separate sticks?
One 8GB stick at a time alone look in the bios to see what the ram timings are being set to.
They are rated at 9,9,9,27.
I recently purchased new memory, 16 GB (2 x 8GB sticks) of DDR3 RAM. I had previously been running on 2 x 4GB sticks, one being slightly different than the other.
After initial installation, everything was normal and the memory was being read correctly by my system. However, out of the blue, my computer started randomly rebooting. I've been taking a look at a few logs in my event viewer, and they are included at the end of the post. It seems to perhaps be related to power consumption, but I don't see how adding memory (as well as later tests) can be attributed to that, especially using a 620W PSU.
To start, I had 24GB total. Channel A contained both 4GB sticks, while Channel B contained both 8GB sticks. I removed both 4GB sticks, and placed the 2 x 8GB sticks in channels A and B. The system began powering on, made it past BIOS, but ultimately either froze or reboot by itself. It occasionally allowed me to log in, however sudden reboots occurred, making the configuration useless. Placing both 8GB sticks into the same channel (I've tried both A and B) prevents the computer from POSTing (or that's my assumption, as no signal is provided to my monitor, and my LED keyboard/mouse do not illuminate). Next, I tried putting back the 2 x 4GB sticks and removing the 2 x 8GB sticks. This configuration worked without issue. I then tried a single 8GB stick, which worked fine. I tried the alternate, which also worked fine (these were both tested being the only memory in my computer). After both 8GB sticks had worked alone, I added the second back (they were in different channels at this point), but I ran into the same problem as before, BIOS completes but then the computer unexpectedly freezes or reboots. I have also entered into BIOS and loaded optimal default settings several times, with several different memory combinations. I have also attempted to use the XMP profiles for the 2 x 8GB sticks, however those do not work (reboot loop). So I am currently writing this using 2 x 4GB sticks. I understand I might not be able to use all 4 sticks as they are different, however I figure 2 x 8GB sticks that are identical should be able to run without any problem. I have also listed my specs below. Thank you in advance for any help!
Also, I'm fairly sure I have the memory channels correct, but just in case I have them shown below:
The DIMM slots appear in order from left to right.
MoBo Label: Channel, slot, slot color
DDR3_4: Channel A, slot 1, black
DDR3_2: Channel A, slot 2, grey
DDR3_3: Channel B, slot 3, black
DDR3_1: Channel B, slot 4, grey
Motherboard: Gigabyte GA-970A-UD3P ATX AM3+
CPU: AMD FX-6300
1 x 4GB stick: PNY Link
1 x 4GB stick: ADATA Link
2 x 8GB sticks: PNY Anarchy Link
GPU: Asus Radeon R9 270 2GB DirectCU II
PSU: SeaSonic 620W 80+ Bronze Certified Fully-Modular ATX Power Supply