spedwolf658 :
Pinhedd :
spedwolf658 :
mdd1963 :
The cpu fluctuating between 800-2000 MHz during normal desktop operation (w/ brief 1 sec spikes to max opening /closing applications), and then ramping up to max during a game or heavy load is 100% normal...and has been for years...
You can set the fan profile to medium/medium high in BIOS to avoid the annoying ramp ups/downs with clock speed, if that is a concern
Why is it that I have never encountered a CPU that has acted like this. When I first turned it on after I built it it didn't do this and neither has any other computer that I have built. When I open Google Chrome or start up my computer it's at such a high CPU usage and clock speed and it almost feels irregular. Anything I open, even scrolling down an article, the cpu freaks out.
That's completely normal.
Modern microprocessors can control the supply voltage and clock multiplier on a per-core basis. They speed up when they have work to do, and slow down when they're idling.
Shouldn't a cpu clock speed be constant on idle? My cpu goes from 65% usage and 4 ghz when pc boots up. And after 4 or 5 minutes, it has a steady usage on idle of 1% for about a second, and it instantly goes to 5% usage and back down to 1. And the clock speed isnt steady on idle. (Not a straight line on task manager with graph) its looks like mountains. Up and down and up and down. There is no way this is normal. Every single friend that games on a pc has never had this problem, as well as my self on other builds.
That's entirely normal.
CPU usage is not a measure of computational complexity or computational load, it's a measure of scheduling.
Windows is a preemptive priority-level multi-tasking operating system.
CPU cores are exposed as one or more logical processors on which the OS kernel schedules threads.
A thread can be either executing (running on a logical processor), waiting (all logical processors are currently executing threads of equal or higher priority), or sleeping (waiting for a system call to wake it up, such as an IO return or timer).
Since logical processors are interfaces to physical cores, something must be executing at all times. Modern microprocessors can be put into an ultra low power sleep state, but it still needs something to execute when it wakes up.
Windows has a process called the "System Idle Process" that runs at priority level 0. There are 32 priority levels in Windows, 0-31. 0 is the lowest and is reserved for the system idle process. The system idle process is created with one thread per logical processor. If no threads of priority level 1 or higher are waiting to be scheduled, a thread from the System Idle Process will be scheduled instead.
CPU usage is simply a measure of how much time the OS schedules threads belonging to processes other than the System Idle Process. This is accounted on a per-logical-processor basis and then averaged out. If you have 8 logical processors (eg, a 4 core microprocessor with SMT/Hyperthreading), each core contributes to 12.5% of the total.
It would be very easy to write a program with a single thread at priority level 1 that simply busy-waits all day long; it never makes system calls so it never sleeps; it will always be executing or ready to execute. If the affinity mask for that thread were set to a single logical processor (tells the OS to always schedule the thread on a particular set of logical processors, rather than as they come available) that processor will never run a thread from the System Idle Process because our wasteful thread from out do-nothing program runs at higher priority (1) than the System Idle Process threads (0). This will show up as 100% CPU usage on that logical processor, and 12.5% overall on a computer with 8 logical processors.
CPU usage looks like a bunch of mountain peaks because threads are constantly switching between executing, ready, and sleeping. A thread may be woken up by network activity, be scheduled, run for a bit, go to sleep for a few milliseconds while it waits for data to be read from a hard disk drive, wake up, be scheduled, run for a while, and then go to sleep until something wakes it up again.