Two types of DDR3 Ram with different speeds and GB total

[GODLY1]

Hi. I recently had to replace a ASUS ROG Maximux Formula VI motherboard due to a power surge from a lightning strike that came through my DSL modem and into the PC. It fried my MB so I bought a replacement off ebay and its the same exact motherboard. Put it all together and everything appeared to be working. All my LEDs were on when they should be and everything until I went to boot up. Got a QCode of 55 on the MB. Memory not installed. I was using 4 sticks of G.SKILL SNIPER 4GB 2133. Took them all out except for one in the first slot. It ran fine. Put the same stick in the second slot and it booted and ran fine again. Put it in the third and coded with the same 55 code. Also the same for the 4th slot. I need at least 16GB to game so I tried more test such as updating the bios, resetting the CMOS and various other methods. Only two sticks would be detected yet all the memory was checking out good. ASUS tech support told me that the memory I was using wasnt listed as compatible to that motherboard even though 4 sticks was running just fine and for 4 years on the same motherboard I replaced. I went ahead and researched what memory was supported that I could find in 8GB sticks on this very site and found a pair. I ordered them from newegg overnight and got them the next day. Put one in the first slot, and the other went in the third, matching colored slot like the manual suggests. Code 55 on attempt to boot. So I repeat the process from the day before with the old memory. One stick in the first slot. Booted and ran fine with 8GB. So I put in in the second slot and booted again. Perfect. Ran fine. Third slot and it coded along with the fourth slot. I was going by the manual and it wasnt going to work that way so I tried it another way. Put one in the first slot and one in the second slot. Works flawlessly. RAM was detected in BIOS and in DXDIAG as 2 8GB sticks of RAM. My question is can I put 2 of my old 4GB SNIPER sticks in the third and fourth slot and make them run with the two 8GB sticks in the first and second slots even though they are at different speeds. The new memory is G.SKILL RIPJAWS in 8GB sticks at 1333. If it will work I will try to sort out why the two slots wont run with memory in them but if it wont work anyway I wont mess with it and use it as it is since Ive already went 4 weeks without my gaming PC

Thanks
Sam

[GSKILL TECH]

Two 8GB modules in A2 B2, 4GB modules in A1 B1. You will need to test and see if they can boot up and work together. First is to see if they can run at DDR4-2133.