Mixing Memory sticks

[makanon]

I have an intel DP55WB motherboard with 2 pieces of 2GB GSKILL [ RipjawsX ] F3-10666CL8D-4GBRM running in dual channel mode.


I want to upgrade to the max ram as possible.


Best way is to get 2 x 4GB DDR1333 CL8 Ram same brand/model type for GSKILL to be safe.
However, does not seem to have a such a type, only got CL9 DDR 1333 and CL9 DDR 1600 in option 3 and 4 below or even some CL7 DDR 1333/DDR1666 ones....
Just wondering whether option 3 and 4 can run ok at lower DDR 1333/same latency with dual channel.

Please advise

Option 1:
[ Ripjaws] F3-10666CL8D-4GBRM (2Gx2)
DDR3-1333 PC3 10666 4GB(2GB x 2)
CL 8-8-8-24-2N
1.5 Volts
XMP Ready for 3rd Generation Intel Core Processors and Z77 platform


Option 2:
[ RipjawsX] F3-10666CL8D-4GBXM
DDR3-1333 PC3 10666 4GB(2GB x 2)
CL 8-8-8-24-2N 1.5V
XMP Ready for 3rd Generation Intel Core Processors and Z77 platform

Option 3:
[ Ripjaws] F3-10666CL9D-8GBRL (4Gx2)
DDR3-1333 PC3 10666 8GB(4GB x 2)
CL 9-9-9-24-2N
1.5 Volts
XMP Ready for 3rd Generation Intel Core Processors and Z77 platform

Option 4:
[ RipjawsX] F3-12800CL9D-8GBXM (4GB x 2)
DDR3-1600 PC3 12800 8GB(4GB x 2)
CL 9-9-9-24-2N
1.35 Volts
XMP Ready for 3rd Generation Intel Core Processors and Z77 platform

[Tradesman]

Of those, best bet would be try option 1 - the same model you have - and even with that there is no guarantee the two sets will play nice, good thing is at 1333, should need nothing more than some slight voltage adjustments, if any problems give us a shout