Question RAM Upgrade

[3greens]

Hello,

I recently purchased a stick of 8gb (1x8gb) Corsair Vengeance DDR3 1800 mhz RAM in order to upgrade to 16GB total RAM.

My specs are as follows:
-ASUS H81M PLUS MOBO
-I7 4790K
-GTX 1080
-Corsair CX550 PSU


My existing RAM stick is a 1300mhz DDR3 piece. Upon delivery of my new Corsair 1800mhz RAM I realised that my MOBO is only able to take 1600mhz maximum... from my research I have found that the 1800mhz can still work but on a frequency of 1600 instead?

I inserted my new stick alongside my existing one and to my confusion the system is still only recognising 8GB of system memory? I have alternated both RAM slots and RAM sticks themselves individually and they both work perfectly on their own but fail to work together to give me 16GB RAM.

If anyone could offer their advice it would be greatly appreciated.

Thanks.

 

[boju]

Might be possible getting them to play nice together but generally mixing ram, especially with differing specs, timings etc is usually a crap shoot.

What we can try is enter speed, timings and voltage manually in the Bios. We'll set timings suited for the 1333 module and maybe set command rate to 2 then see how it goes. These settings are usually found in the memory page in the Bios. Then if need, up dram voltage .01v till we get to 1.55v.

Need to get the timing values which Cpuz SPD tab will provide. Can you post a screenshot of this please if possible. Use imgur to post images.

 

[boju]

Sorry, post SPD tab for both memory please