Mixed DDR3 question

Hi -

This is my first time building my own pc as well as trying to overclock. Originally I had purchased 4GB Crucial 1333 (PC3-10600) ram and then decided to pick up 4GB G.Skill 1333 (PC3-10666). I currently have all 8GB in use with the G.Skill as the primary. The computer boots fine and I have been able to overclock from 2.9 GHz to 3.5 GHz. I am not stable when I run Prime95 though so I was wondering if it would be better for me to remove the Crucial DDR3 or if I just need to back off the overclocked speed a little.

MSI 870-G45
AMD Athlon ii x2 245 2.9GHz
4GB DDR3 G.Skill 1333
4GB DDR3 Crucial 1333
250GB harddrive 7200 RPM
nVidia GeForce GTX 460 768MB
Thermaltake 600w

I understand it is not the "best" way to do it, but I initially used MSI's OC Genie Lite which is what got the overclock up to 3.5 quickly.

Thanks for help/suggestions!

You may need to increase your cpuNB voltage slightly, stock is generally 1.175, give 1.2 or 1.22 a try and see if that stabilizes things.

The more ram you install the more you stress the memory controller (which resides in the cpuNB), so sometimes you need to give it a little bit more voltage.

It's also worth noting that if you're simply changing the HTref you've overclocking the ram, HT Link and cpuNB as well as the cpu. The HT Link doesn't like being over 2000 much at all, and going slower then that doesn't hurt anything but multi-gpu setups as long as it's over 1500 or so.
The cpuNB defaults to 2000mhz, it should be happy on stock voltage up to 2400 or so, though this number may be significantly lower given that you're using four sticks of ram.

thanks for the input. Just to clarify, you are saying that there is no reason to remove the Crucial ram but make changes in the BIOS to account for the fact that I am using more ram?!