Is mixing RAMs of different capacities bad for a computer??

Solution
It's not a problem at all.
Having identical dimms in a pair allows the memory to operate in dual channel mode, which is faster, but adding a second stick like this will certainly not reduce performance compare to a single DIMM.
There could be compatibility issues, but you'll find out pretty quick when you try it and it certainly won't do any harm.
It's not a problem at all.
Having identical dimms in a pair allows the memory to operate in dual channel mode, which is faster, but adding a second stick like this will certainly not reduce performance compare to a single DIMM.
There could be compatibility issues, but you'll find out pretty quick when you try it and it certainly won't do any harm.
 
Solution