My RAM is rated at 3600 MHz. DDR4, 2 x 8GB, slots 2 and 4. In the BIOS, I have (I think) enabled XMP Profile 2. When I check CPU-Z, I get (I think) 933 MHz:
FIGURE 1
When I switch to the SPD tab in CPU-Z, I get the following:
FIGURE 2
Here's a picture of the relevant section of my configuration in UEFI, which I think indicates that it's running at the rated 3600 MHz:
FIGURE 3
Is my memory running at 3600 MHz (~2x1798=3596) or 1866 MHz (2x933) or some other speed?
The displayed numbers are not exact. In any case, since the memory has dual channel you need to multiply the displayed number by a factor of two.
As "933 x 2 = 1866", your memory's official rating is somewhere near to that number, rounded to 100.
Just to note that the official rating (as described when you bought the memory), is almost never exactly what you get.
Despite the fact that my UEFI was showing the memory at 3600 MHz, no application in Windows reflected that. However, changing the DRAM Frequency in UEFI to 3000 MHz caused caused CPU-Z to show an 'Uncore Frequency' of 1497.0 MHz (x 2 = ~3000 MHz) and Task Manager to show a speed of 3000 MHz (up from ~2100 MHz).
In short, the UEFI lied about the actual speed, but Windows Task Manager very clearly showed the speed.
