Your RAM is fine. Give this a read: MEMORY FAQ (please read before posting)
In particular, things to note:DDR SDRAM
: Double data rate SDRAM. The core-clock speed of a DDR SDRAM module is synchronous with the CPU bus, however data is sent on both the rising and falling edge of the clock signal effectively doubling the memory chip's throughput.
CPU-Z reports RAM differently than the manufacturers do. CPU-Z reports on the clock signal. Manufacturers like to make the numbers as high as possible so they count the rising and falling edge of the clock signal. I.e., to get CPU-Z reported number to equal the number manufacturers push you have to double what CPU-Z says. 666 x 2 = 1333 (approx).