Can you run 1333 and 1600 RAM together?
Well, yes DDR3 1600 is compatible with DDR3 1333 MHz. But using them together both will have same speed.
Is there much difference between 1333 and 1600 RAM?
1600 is 1600 MHz, and 1333 is 1333 MHz. So the 1600MHz memory would (or should) be faster.
Can I run my 1600 MHz DDR3 RAM on a motherboard which supports 1066 1333 MHz DDR3 RAM speed?
So the answer is that 1600 Mhz memory modules may not work in a slot that supports only upto 1066 Mhz. However the 1333 Mhz RAM worked.
Can I use 1066 and 1600 RAM together?
Even if they’re 100% identical except for the clock speed difference, they might STILL not work together. RAM is finicky like that. Suffice to say that it’s not very likely to work even if the modules are physically the same.