I'm running Windows 10 Pro 64 bit, 16GB of Ram on an Asus Sabretooth 990FX motherboard and an AMD FX 8150 Black Edition 8 core cpu. I am also using an AMD\ATI R7-370 PCI-E video card. I was using all 8 cores but after updating my video drivers (which includes amd drivers for the mb) to version 16.6.2, now my system says it's a 4 core cpu! I rechecked the bios and it still has "all core active" set to auto. Any suggestions? If I roll back the video drivers, it will automatically install 16.6.2 again. I noticed with 16.6.2 that when I open a webpage or a game, my cpu fans speed up. I just used the uninstaller from ATI and reinstalled 16.3.2 and the fans are not speeding up but it still only shows 4 cores not 8.
WIN10 allows user configuration of the CPU cores. You'll need to have both the BIOS and the O/S set to use all eight cores.
There are a variety of threads / YouTube videos to assist you if you are unable to find the proper WIN10 settings in the "help" menus.
Win10 will park processor cores to save power with the default computer power plan 'Balanced'. Setting your computer power plan to "Performance" will 'unpark' them all.
All FX-8000 series CPUs contain four clusters or "modules", with each module containing two integer cores. Each module contains only one floating-point core. Therefore, the way the OS is concerned, and to schedule threads correctly, it identifies each cluster as a "core" to spread the load evenly across each shared floating-point core. Each integer core is addressed as a logical CPU.
That means, us FX-8000 guys have 4-core, 8-thread processors. We do not have true 8 core CPUs, and the OS identifies it as such.
Read up on CMT (clustered multithread) and the Bulldozer architecture.
Thanks for the info. I checked my BIOS and the Asus Core unclocker is enabled and the cpu core activation is set to manual which activates cores 3 to 8. When I built the system 4 years ago, I did the msconfig trick, and it showed 8 cores. I recently bought an asus pci-e r7 video card. After installing it, there was newer software for it. The "package from ati" included amd drivers. That's when I found my system now shows 4 cores. I uninstalled those drivers, rebooted and put back the original ones, but it still shows 4 cores. Thanks everyone for your time and help.