Processors

[nyks]

[jamesx380fx]

Try Reseting your bios settings to default, do the same for RyzenMaster if you've made any changes there recently (do it anyway even if you didnt, just in case) then check cpu-z again.

[misterj]

nyks, the most likely cause of this, seen many times, is not installing a fresh copy of Windows after changing the processor.  Enjoy, John.

[nyks]

I did it, and nothing changed

[nyks]

If i install a fresh windows CPU would work fine?

[black_zion]

Have you updated that motherboard BIOS to one which has support for the 3900X?

[misterj]

nyks, probably.  As black_zion points out, you need to make sure you have the correct BIOS. Enjoy, John.

[nyks]

My MOBO is aorus ultra x570, and i have F10C bios, how do i check compatibility between CPU and BIOS ?

[nyks]

I just install Windows it shows me all cores, but when i select from “Ryzen Master” a profile “Gaming mode” it turns back to 3 cores

[jamesx380fx]

Dont use gaming mode, it doesnt really help much in gaming scenarios and in some cases your ending up losing performance due the lower core/thread cound. Also, stop messing with RyzenMaster settings unless your sure of what your doing or want to do some very specific tweaks to your CPU.

If you've already got gaming mode enable in RyzenMaster, reset all settings to default and restart your PC and check again.