Octopus Overlords

Maybe someone here knows. I'm working with support for a program, and I'm trying to monitor CPU usage. The problem is that while Task Manager shows that particular program is using ~19%-22%, the same program in resource monitor is showing 8%-10%, about half. And this is watching them in real time, side by side.

Any idea why?

I am not on a windows machine to check, but the quick guess is that one is showing individual core usage and the other is showing usage of overall capacity. Another possibility is one has the usage split into multiple threads and the other is showing aggregate usage. These are just guesses based on the data you have supplied. Our windows admins should have better answers.

I don't have the time to look, but does windows 10\11 have perfmon. I know servers do, but never really checked deskop os. You might be able to use that and see if you see the same thing

Task Manager and Resource Monitor use a completely different denominator in their CPU% calculation. Task Manager is looking at processor utility. Resource Monitor is looking at processor time.

Usually when people talk about "CPU usage", they really want to know CPU time as percentage of total CPU capacity. So I'd probably stick with what Resource Monitor (or Perfmon, if you have it) tells you.

Ok, you've all managed to confuse me. I'm not a tech, and I am terrible with math (which is one of the big reasons I am not a tech.)

I know that I have a program (it's a program that manages the lighting on various devices in my system - keyboard, fans, etc.), which I use to avoid needing to install four or five different pieces of software (one from each manufacturer.) If I use it in the mode I prefer, it shows 20%+ CPU usage in task manager, while if I use it in a more basic mode, it shows ~3%.

Support, having seen screenshots of my Task Manager CPU usage, and after three weeks of basic troubleshooting, asked me for Resource Monitor screenshots. I sent those, and sure enough, even though Task Manager was showing~20%, Resourced Monitor was showing ~8% usage. They're not worried about 8% usage. But Task Manager is still showing ~20% plus.

So is this thing using 20% of my CPU or isn't it?

<rant>And why does Microsoft have to use the same terminology for, apparently, three different measurements with no hint as to which one matters?</rant>

Blackhawk wrote: ↑Tue May 02, 2023 6:20 pm So is this thing using 20% of my CPU or isn't it?

It's not. Really.

In the most non-technical terms that I can describe, you don't care about your "processor utility" for system performance. It's a number that shows how much actual work the processor *could* do if it was never idle.

You only worry about "processor time" - resources that the CPU spends actually running your program. Which is not something Task Manager is telling you. Stick with Resource Monitor.

Blackhawk wrote: ↑Tue May 02, 2023 6:20 pm <rant>And why does Microsoft have to use the same terminology for, apparently, three different measurements with no hint as to which one matters?</rant>

Developers have been bitching about it since Windows 8 (which is when Microsoft, in their infinite wisdom, reworked Task Manager).

Let me see if I can explain this:

Task Manager's CPU utilization graph is pretty... meaningless, esp. on modern PCs, with its ability to upclock/ downclock to conserve power, as well as turn off several cores when it's a multi-core processor. Much like you would not measure your car's performance when it's running only on 2 or 4 of its 8-cylinders, or in eco-mode.

The CPU utilization makes you think "O NO, even when computer's idle the extra stuff is taking up 20% of background process!" But keep in mind that there's a LOT your computer does in the background, from updating the mouse to checking the HD cache and its own swap file, and bajillion other tasks. And your CPU downcycles to minimal frequency and/or turns off some cores so it's operating in reduced capacity mode to save power, since it doesn't need "all 8 cores" to do background tasks. So this "feels like" the background tasks are taking up a lot of CPU cycles... but it's only for the "reduced available power" state.

Yet this is obviously not a "true" measure of your CPU's utilization, so Microsoft try to have it both ways by creating this "Processor utilization" measure as a percentage of work it *could* complete **if it were running at nomimal performance level** without "burst clock" or such.

Which means if the CPU is capable of burst mode, or has extra cores that can be engaged in performance mode, the CPU utilization can exceed 100%.

Which will panic some people, probably thinking their CPU is melting or they're getting hacked, so the graph itself is capped at 100%.

That pretty much makes it useless, unless it is constantly exceeding 85%, which can indicate some sort of CPU bottlenecking.

In other words, there's no real way to get meaningful information as to whether something is causing problems.

Blackhawk wrote: ↑Thu May 04, 2023 11:21 pm In other words, there's no real way to get meaningful information as to whether something is causing problems.

Use something OTHER than task manager.

Kasey Chang wrote: ↑Fri May 05, 2023 11:50 pm

Blackhawk wrote: ↑Thu May 04, 2023 11:21 pm In other words, there's no real way to get meaningful information as to whether something is causing problems.

Use something OTHER than task manager.

Any suggestions to casually make sure that none of my background programs are eating too many resources, without requiring archaic command lines or a degree to use?

I personally just use Process Lasso, which is nagware only when you boot it up, or bring up its UI. Otherwise, it stays in the tray and looks like your task manager. It automatically downshifts processes that seems to take over your CPU entirely to make sure your system can handle other tasks in the background, without affecting app speed (much). And it keeps a log that you can view on how much of this lasso-ing it has to do on your behalf. If you have more than a dozen "ProBalance" events daily, you're either running a lot of heavy loads, or you have something eating CPU power in the back you weren't expecting. I generally only have about 6 or 8 at most.

Blackhawk wrote: ↑Sat May 06, 2023 3:24 pm

Kasey Chang wrote: ↑Fri May 05, 2023 11:50 pm

Blackhawk wrote: ↑Thu May 04, 2023 11:21 pm In other words, there's no real way to get meaningful information as to whether something is causing problems.

Use something OTHER than task manager.

Any suggestions to casually make sure that none of my background programs are eating too many resources, without requiring archaic command lines or a degree to use?

I love process monitor, and it's free! It does edge dangerously close to that "degree to use" redline you mentioned, though.

https://learn.microsoft.com/en-us/sysin ... ds/procmon