Why Does CPU-Z Indicate DRAM’s Max Bandwidth Is Only X?
The maximum bandwidth is a setting found in the SPD tab of the program and is often misunderstood. Many people take it literally.
SPD is stored on your DRAM module and contains information on module size, speed, voltage, model number, manufacturer, XMP information and so on. What appears in the Max Bandwidth pane of CPU-Z is actually the DRAM’s default boot speed. This is what the DRAM boots up to without XMP, AMP, DOCP or EOCP enabled.
You can see an example of this in Figure 2A above, where it shows the max bandwidth of PC3-10700 667 (or a data rate of 1333, the motherboard’s default). Yet these are clearly 2400 DIMMs and can run at a frequency of 2400 (Figure 2B).