I have one 8GB DDR3-1333 memory stick (click here inserted into one of the two DDR3 memory slots on my motherboard which supports up to DDR3-2400 MHz memory sticks. I have run two diagnostic tools “CPUID CPU-Z” and “Speccy” and both report memory frequency as 666.5MHz which is half of 1333MHz. For what I do (nothing memory intensive) my RAM is adequate but I am confused. If my RAM stick is 1333MHz then why is it only operating at half speed? Is it a BIOS setting or is not possible to tweak RAM speed? Thank you in advance of any help.
Thanks for your answers. More questions arise from this: - I am only using one DDR3 slot with 8GB DDR-1333 module in it. Am I correct that using both DDR3 slots is faster than using one because they are working in parallel? I am not doing memory intensive stuff and I am happy with how things perform so I reckon my questions are only because I like to understand what goes on inside my PC. I could probably get away with 4GB RAM in the form of two 2GB DDR3-1600 modules (faster than 1333). This would be quite cheap at £36 but would any speed increase be noticeable? If not then I'll leave well alone.
You are right that using both memory slots should be faster as the memory interface will be able to operate in dual-channel mode, theoretically doubling bandwidth. However, you will likely gain more from having 8GB than you lose from not having dual-channel enabled.