Memory mix

[doa]

What are the effects of useing mismatched ( ie same capacity with different timing) memory on Windows 7 system?

[WiseCleaner]

We can not understand your description clear enough. 

 

As we can tell, if the difference is just different memory, ddr2 and ddr3 would be incompatible;

 

If its memories are same, same ddr2 and ddr3, but different frequency, then the high frequency  would be changed to low frequency.