CPU-Z says my PC3-10600 1333MHz RAM is actually PC3-10700 667MHz. Do I have 1333 or 667 MHz RAM?

Solution 1:

You have 1333 DDR (Double Data Rate) RAM.

The RAM itself runs at 666MHz, but because it is "double pumped" its equivalent data rate is twice that, hence 1333MHz.

Solution 2:

You do indeed have PC3-10600. CPU-Z shows only the half of it because DDR RAM like the names says - Double Data Rate - can transfer twice as much data on one I/O bus clock, than the actual IO frequency which CPUZ shows.

If you want to dig deeper in this topic check this link, it describes it really well.

Solution 3:

Actually its not 10600 but 10700 as the OP says. and it runs at 1334 (2x667) to be exact. Sisoft Sandra measures the same as the description.