13 minutes ago, ASH7 said:
Looks like DDR4-4400 MHz is too aggressive for the i7-8700K.
What brand and kit model of RAM did you buy?
- Enable XMP (so the timings, voltages are set to XMP spec)
MANULLY change the DRAM frequency ratio from [Auto] to DDR4-3600 / 3400 / 3200 / 3000 in BIOS
- Try 3600, and if it doesn't work, then work your way down the frequency list
- Save an exit, and see if works
Keep in mind Intel only *guarantees* up to DDR4-2666, so anything above is considered overclocking.
- But Intel CPU's Integrated Memory Controller (IMC) is pretty robust; DDR4-3200 ~ 3400, at least, should be easily doable
- Again overclocking anything, nothing is 1100% guaranteed.
The motherboard design / topology (e.g. your AsRock Z390 [which model?] ) plays a role, too.
Not just the "silicon lottery" of the CPU.
Task Manager is really finicky.
Some users see the actual RAM frequency rating, others see the effective rating.
MY Task Manger shows the effective speed, so DDR4-3400. CPU-Z shows 1700 MHz.