I have a program that uses 100% of my CPU according to a freeware CPU meter.
Is this hard on my computer? Will it shorten its life?
I’m 99.44% sure that your CPU is always doing something, so no, it shouldn’t be too bad.
It might. If your CPU is working that hard, it’s gonna get mighty hot and heat shortens their life. You might think about an additional case fan, or a processor upgrade. Are you having stability problems with that program? Usually when I have something pegged at 100%, a crash is not far away. What OS are you running?
Your CPU is always being utilized at 100%. If no combination of user programs is currently utilizing all of your CPU cycles, the dummy process, “System Idle Process” (in Windows, at least), will take up the slack.
The only possible detriment to a process running at 100% CPU usage is that it may, depending on its priority, “starve” other processes for CPU time, resulting in noticeable slowdown when using other programs.
The CPU is always fetching instructions, yes, but how much it is doing depends on the workload. The power consumed depends on the amount of switching in the CPU. I’ve provided special tests to maximize power consumption, and during burn-in (where you run the chip in an oven to bake out early reliability problems) you apply tests to increase the amount of switching. You can go overboard - I know of a case where someone trying a new test method that caused a lot of switching got the chip so hot that it melted the very expensive board it was on! So running at 100% is not a good idea.
That said, there is no reason you should be. Does your meter tell you which programs account for this? The last time I worked on a PC with a 100% load it was due to a virus. Most of the time the machine should be relatively idle looking for input, and of course doing all the other stuff the OS is doing. Unless you are doing some heavy gaming or number crunching, this might be the sign of a problem.
System Idle Process may keep the proc busy, but it sure isn’t keeping it BUSY. Fire up something like SETI@Home, and watch the core temp go up. System Idle is just that - idle.
Yes it will. Not by much, though. Other components of your system will die before your CPU will. If you upgrade to a new system at least every 5 years, there’s no reason to worry.
And… what Voyager said. That amount of CPU usage will make your system unusable. Windows is especially bad at handling high loads for an extended period of time.
I believe the difference is that the “system idle process” is using 100% of your cpu cycle but not doing anything “hard”. The thing with CPUs is that it can only do one thing at a time so 100% cpu usage is a little misleading (it’s always at 100% when it’s being used in any given way). The OS gives the illusion of multi-processing but in reality the CPU is switching from one app to the other very quickly.
System idle process keeps the cpu from harm IIRC. Something about the CPU needing something to do all the time (google is flooded with questions about it but no serious answers except “don’t worry about it”).
And I have never had a CPU die on me in the 14 years of computer building.
As others have said, your CPU is always doing something. There is no way to tell a CPU to just sit there other than shutting off its power. Even the idle process is fetching and executing instructions. However, the fact that some part of your CPU is busy doesn’t mean that all of it is busy. You’re never going to have every single transistor on the chip change state at the same time, anyway.
What does this mean in terms of lifespan? We’re dealing with a single solid-state device. It’s not like a disk drive, which contains a motor. The paths in a CPU chip don’t wear out because of the number of electrons traversing them. The enemy of electronics is heat. Each time a transistor changes state, heat is generated. If your system has adequate cooling and you’re not overclocking, then keeping your CPU “100% busy” will have no deliterious effects at all. If that sucker is heating your 2,000 square foot home, then you have a problem.
Disclaimer: I have designed CMOS chips and written a multi-user, multi-tasking operating system, so I understand how these things work. On the other hand, I haven’t done either of those things since CMOS chips went sub-micron, so I’m a bit out-of-date.
Thanks for the answers! I guess it is not a problem then. My cooling system seems fine. The program does not become unstable, unlike some other programs I have had crash on me when the CPU meter went too high (such as vst sequencers). I think this program was designed to go full out.
that_darn_cat: My os is xp pro.
Is your CPU really running at 100%, or is it mostly idle? I guess MS put in the system idle process so no one would wonder where all their cycles went.
Voyager, all I know is that freemeter (a freeware CPU monitor tool) and other CPU monitors report that when I run this program, CPU is at 100% when normally it is at 0% and very low numbers for most other programs (1-2%).
Actually, modern operating systems halt the CPU when they’re idle. The HLT instruction causes an x86 CPU to basically shut off until it receives an interrupt. Interrupts are happening all the time, so it doesn’t shut off for long, but the CPU really is using less power and producing less heat when your computer is idle.
Cite? I rather doubt it, since starting up a processor (not the OS, the processor) takes a lot of steps. I rather suspect it is busy checking the queue for stuff to do, etc.
Processors however do have a lot of hardware to gate clocks that basically turn off regions that aren’t being used in order to conserve power. That’s a lot different from a halt.
No, that’s what’s done. Here is an excerpt from NetBSD/i386’s cpu_switch routine — note the hlt in the middle.
...
idle_loop:
/* Try to zero some pages. */
movl _C_LABEL(uvm)+UVM_PAGE_IDLE_ZERO,%ecx
testl %ecx,%ecx
jnz idle_zero
sti
hlt
NENTRY(mpidle)
idle_start:
cli
cmpl $0,_C_LABEL(sched_whichqs)
jz idle_loop
idle_exit:
movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh
sti
...
I had a bank of new DELL machines we ordered without an OS. We hooked them up to a remote power switch with a current meter. It read 6A when they were first booted — prompting for media with a bootable OS. My best guess is that they were in a busy loop waiting for a keystroke. But after we installed Linux, Win XP, and NetBSD (it’s a OS test-bed), the current draw was less than 3A.
Ah, I see. They don’t make halts the way they used to. It’s been ages since I’ve programmed in assembler - not since 8080m and PDP-11 days.
Partly true. Certainly how it was but the new Pentium processors with Hyperthreading in them can actually process multiple threads simultaneously as if there were more than one processor in the system.
Satasha:
In windows XP (and 2000 I think) you can just hold down ctrl and alt and del at the same time to see the task manager, then go to the “performance” tab and check out the “CPU uage”. You don’t need a freeware program. You can also see how much % of the CPU each process uses. (The “System Idle Process” is the leftover %)
Satasha:
Ok I see you’re saying that the actual program uses about 100% of the CPU… well just remember that the value of computers halves about every 18 months so by the time the CPU dies (if it ever does) you’re computer would be pretty worthless. As long as your CPU has good ventilation and doesn’t overheat (your computer has an alarm for overheating) then it would be fine. (You can even lower the temperature at which the alarm begins and also lower the temperature when the power is automatically cut off). BTW, there are some people who even run things at 150% or more than the CPU’s recommended full speed (overclocking) - sometimes without proper cooling…
BTW, lots of people who do rendering, etc, have the computers on 24/7 and use 100% of the CPU and the computers would last for years…