Compatibility question ddr2 ram

Solution
From what I can tell, your RAMs have different speeds. You can see that the one says 555MHz and the other 333MHz (you double that to have your effective speed, so 1100MHz and 666MHz respectively).

When 2 or more different speed of RAM are installed in your system, the BIOS will make all of them work in the lowest speed to be compatible. In your case 666MHz. It does not harm your system at all.
From what I can tell, your RAMs have different speeds. You can see that the one says 555MHz and the other 333MHz (you double that to have your effective speed, so 1100MHz and 666MHz respectively).

When 2 or more different speed of RAM are installed in your system, the BIOS will make all of them work in the lowest speed to be compatible. In your case 666MHz. It does not harm your system at all.
 
Solution