VCCSA helps stabilize the processor’s memory controller. For the most part the ROG UEFI BIOS left to ‘Auto’ will scale fine for most CPU/memory combinations. Some CPUs may need manual adjustment. and the maximum we have needed to use is 1.15V. However, some CPUs do not respond well to anything over 1.05V; such processors usually overclock memory fine at stock settings – even though they prefer lower voltage. Start low (default is 0.80V approx.) and work upwards. The relationship between voltage increases to VCCSA and stability are non-linear. There are certain ranges of voltage which may exhibit worse stability, once you go past them (higher or lower) stability improves once again. Try 1.02V for memory speeds above DDR4-2900 as a starting point and work up or down from there.