Only 2133 MHz RAM is active despite DOCSIS enabled
Only 2133 MHz RAM is active despite DOCSIS enabled
I can look up the XMP/DOCP profiles for your RAM using CPU-Z. It might help to pick a different profile if needed. Running four sticks tends to be trickier, especially with higher clock speeds. You could start with two sticks first. ~Note: If you're looking for optimal performance, DDR4 on Zen 3 usually hits around 3777 MT/s. Beyond that, the memory speed drops significantly unless you boost it further (though that might limit you to about 1:2). A higher overclock of around 1900 MHz could push it to 3800 MT/s, which may affect overall performance.)
It varies by board; most will switch to desynchronized mode once you exceed 3600MT/s. For manual overclocking, most chips cap around 1900MHz FCLK, though some high-quality models reach 2000MHz. There are exceptions, but dual CCD chips like the 5900X make 4000MHz unlikely. Generally, this board struggles with dual-rank memory, so you're likely to hit about 3800MHz even without FCLK sync. Try removing two DIMMs to test if you can reach 4000MHz in 1:1:1 mode, but success is uncertain and may require slowing down the speed.