4x Memory Slots: Combining paired DDR3 1600 and 1333 RAM?

[nillafudge]

I've got a Gigabyte GA-Z77X-D3H mobo with 4 DDR3 dual-channel memory slots.

I'm currently running 8 GB of DDR3 1600 (Kingston HyperX, 4gb x 2) paired in slots 1 and 2 with 3 & 4 empty.

I have 4 GB of DDR3 1333 (G. Skill NS, 2gb x 2) sitting around I was thinking of adding. Would running the 1333 paired in 3 & 4 be fine with the 1600 in the other slots since this is dual-channel, or do I need to keep size/frequency consistent in all four slots?

Also, would I need to clock the 8GB of 1600 down to 1333 if I added the additional memory? If so, would this mean keeping the current 8 at 1600 would be better than adding 4 and lowering the frequency?

Thanks in advance for your help!

 

[rojodogg]

Have you checked to see if your RAM is running at 1600mhz? Most MOBO re-clock RAM speed to 1333mhz and you need to adjust them up to 1600 in the bios.

I would remove the 1600 and install the 1333 and then speed them up in the bios so that they are at 1600 then save and install the 1600 in slots 3 & 4.

 

[inzone]

If you install the 1333mhz ram with the 1600mhz ram then they will all run at the slower speed. 8gb of ram is sufficient for most applications and all gaming and with gaming even if you add the ram the computer will only use what it needs and there are no games that require more than 6gb of ram.
Is there a reason why you need to add the extra ram? Are you doing any video editing or video rendering with 3D graphics.

 

[Nahtangnouv]

If your mobo can support the 1333 go for it, but I suggest putting one 1333 and one 1600 in slot 1&2 and the same goes with slot 3&4