DDR3 pairing or varying speeds

[stewartd1980]

Hello, thanks in advance to anyone who can answer this.

I have the following:
-G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL8D-4GBRM

-G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL9D-8GBRL

I have all of the above running in my system in their appropriate dual channel slots. My PC is recognizing 12GB worth of RAM and everything 'seems' fine.

My question is this; Am I shooting myself in the foot, performance wise, by having dual channel DDR3s of differing speeds running at the same time? Would I be better off not having one of the following in my system. Benchmark tests seem to indicate that having all in is better but I am still a little wary.

Secondary question; Can anyone think of any other issues this might cause me in the future? I really can't think of any but am a little concerned since I don't understand dual channel all that well.

 

[JDFan]

Since the 8GB. is slower in both timings and clock rate they will slow performance somewhat (All Modules have to run at the same speed\timings so the system will have to be run at the lower rated module speed - or a speed that hey can run stable at)