I did an upgrade of my system before moving on Windows 10 Pro.
The upgrade was from Phenom 2 6core 1090 to 8core FX 8320, from MSI HAWX 6870 to SAPPHIRE NITRO 380X, from 4 Dimm G.Skill Sniper total 16GB of 1600speed (not working well at that speed on my phenom so i don't risk and change it) to Kingstone Fury 1600Speed of 2Dimm total 16GB (Working perfect at 1600speed), as also 3 new HDD drives at raid0 which i always using that kind of array. I keep my beloved Asrock 890FX Deluxe5 (my opinion if not the best, one of the best 890FX Motherboard). My problem is that in lot of games (especially at UE3-4 but not only on that engine) after a while (30-50min) the first core (always the first) going over time to 100% and the other cores lowering till 1st core reach 100% and all the other 7 reach almost 0-5% then the game is unplayable-bottleneck with really really low fps (haven't yet check if that happens also to long time consuming rendering, as i'm also use the machine for some 3D scenes i make).
Till now i have enable disable almost everything from BIOS, i have Unpark all my Cores, forced the programs to run all Cores, and did everything i have found as a "solutions" over developers forum that provided by other users (as long devs don't give a ****), but eventually the same things happens at the end. Even newer games that mentioning as multicore use have that problem (i've already mention that cores start normally but loosing % as time pass and force 1st core to reach higher %) The only game that work the best is GTA V, is looks like great optimization or i don't know what else is.
Please provide any help you can because that is really frustrating, and that upgrade in my "damn" country (Greece) cost me 2monthly+ payout.
PS: My BIOS Version is the last (2.0).
Thank you in advance for any help will provided.
In Win10 the power plan you select influences how many cores are active. Make sure that you are using the maximum performance power plan and/or create your own if it is still an option in Win10 as it is in earlier versions of Windows.