Curious about Turbo Mode of CPU

[DaveLembke]

Back in the day Turbo use to be a button on my computer to switch from 12Mhz to 16Mhz and was manual... These days they have dynamic Turbo's where they on the fly will do this without a push button.

I just bought 2 of these boards for a low cost workstation project and was curious at what point the Turbo would trigger, is it a certain percentage of CPU utilization in which it will trigger or only when the CPU is at 100% it will ramp up the clock to 2.7Ghz to try to charge through a work load to get to a certain CPU utilization to where its back to below 80% in which the clock will go to 1.7Ghz, as well as does the OS have to support a Turbo instruction to get to 2.7Ghz vs just 1.7Ghz or I dont have to worry about say using Linux on it and it being bottlenecked to 1.7Ghz etc because of a missing instruction for the CPU ( APU in this case ). Additionally are these able to sustain a constant Turbo speed without running too hot or does it run to Turbo and then when it gets to a certain temp it shuts off Turbo and then when it cools runs back to Turbo again and so it could be 1.7Ghz then 2.7Ghz and then 1.7Ghz and then 2.7Ghz for a slow / fast cycle during heavy CPU/APU loads to stay within an operating temperature margin and not roast?

I havent had any newer systems with Turbo enabled CPUs. I have 2 systems a AMD FX-8300 and FX-8350 and the motherboards dont support Turbo so they stay at 3.3 and 4.0Ghz, so I know that the board has to support it first of all and then I am not sure about if the OS has to as well. The only alternate clocking I have experience with is the Cool n Quiet or Stepping that Intels have to underclock but go full clock when needed. Not sure if this Turbo is just an on the fly overclock or if they are selling underclocked CPUs/APUs and going full clock is what the Turbo is etc.

New territory and so I figured I'd ask for info on this to know what I just bought myself into and expectations of the Turbo behavior when the system is running.

https://www.newegg.com/Product/Product.aspx?Item=N82E16813138448

[BC_Programmer]

The old "Turbo" *reduced* performance. When Turbo was ON, the CPU speed would be reduced. The purpose was for software which relied on cycle specifics. The IBM AT introduced the Turbo button which was also featured on most clones- it reduced the 12Mhz 286 CPU down to the 4.77Mhz Speed of the XT and original IBM PC, so that software that was written cycle-dependent would run correctly- Later systems effectively reduced to speeds for the previous generation. I had a 286 which would "Turbo" down to 4.77Mhz, a 386 which would "Turbo" from 40Mhz to 12Mhz, and a 4867 that would Turbo down from 120Mhz to 33Mhz (The 386 and 486 had nifty LED digit displays next to the turbo button as well)

It isn't really related to SpeedStep, TurboBoost, Turbo Core, etc. Except in Name.

As far as I can tell the specific details of how the current stuff works aren't revealed. It fundamentally tries to intelligently determine when to overclock the chip based on Processor load but apparently it's not as simple as the utilization because people have reported issues with games or other software underperforming when it is enabled. They throttle at higher temperatures as before and the feature is a feature of the CPU- so it should work even if you boot, say, MS-DOS from a floppy and run an intensive task.