Very laggy game but CPU used at only 30%

[nukkxx5058]

The game becomes VERY laggy (3 or 4 seconds for 1 second real time) when massive arty barrage starts. The problem is that my CPU is only used at about 30-40 %. (with priority high and affinity = all cores checked). And same for RAM.
It seems that something is limiting the CPU.

The below scenario is VERY laggy as soon as arty starts its massive barrage. There are only 281 AU so my guess is that there's a problem and that something is preventing the CPU from being used in full. This happens each time massive arty or guns are fired if I recall well.

And my CPU is used at only 30-40 %
AMD Ryzen 5 1600 Six-Core 3.20Ghz
RAM 16 GB
Radeon RX 580

To reproduce: open the save, zoom-in if necessary then just unpause , wait a few minutes after more salvo are fired and watch. After a few minutes (say from z12:09), when all arty are firing, it's totally laggy but CPU is not used in full.

Please also have a look in your task manager to check CPU occupancy rate.
Any idea what could cause this ? Can you guys reproduce it on your PCs ?

Thank you.

PS: yes, I know the arty is firing a lot of stuff but it won't explain why CPU is not working in full.

Testing CPU speed and lag.zip

(112.3 KiB) Downloaded 21 times

[nukkxx5058]

Screenshots

LAG_CPU_NOT_USED.jpg (334.54 KiB) Viewed 1646 times

LAG_CPU_NOT_USED2.jpg (298.86 KiB) Viewed 1646 times

[nukkxx5058]

Oops, I thought I posted this in the tech forum ... sorry ... can it be moved ?

[BDukes]

It is slightly chuggy/laggy on my new computer but I'm sure I only noticed because you pointed it out. I tried turning off all display features. No change. Added additional spotters. No change. The only thing I noticed is the chugs seemed to correlate with a detection (notice when the 1-second detection data block appears). Also, notice the second big salvo missile curl at the end of their track if their target is lost/destroyed. Not sure if that is part of the issue.

Mike

[nukkxx5058]

Did you wait long enough that all arty fire like mental with plenty of missiles flying all over the place ? This is when it starts to lag a lot for me.

And why is my CPU used at less than 50 % ?

[nukkxx5058]

It is slightly chuggy/laggy on my new computer

Is it a quantum Cray ?

[BDukes]

Jeez no good deed goes unpunished with you.

Processor AMD Ryzen 7 5700G with Radeon Graphics 3.80 GHz
Installed RAM 32.0 GB (31.3 GB usable)
Win 11
1TB SSD

Now can I get back to watching the end of the world

[nukkxx5058]

Jeez no good deed goes unpunished with you.

Now can I get back to watching the end of the world

[nukkxx5058]

So I checked my power plan and min/max CPU usage is 100%, high performance.
It really puzzles me that my CPU is not working in full while the game is extremely laggy
Anybody else did run the test with the above save ?

[ultradave]

I ran your save. It is a bit laggy/jumpy while all those rockets are in the air, and at x1 each second takes about 2. At x5 it runs at about 1:1, but still is laggy. Once they hit and kill a bunch of the targets, things are pretty normal, until the second wave of rockets is in the air, then back to the lagging, until they all hit. The smaller 3rd wave is normal.

My CPU utilization was running 50-60%, with one jump up higher (not sure why - didn't really correlate to anything going on - picture attached). I think that utilization is pretty good for mine, because I run it in a Parallels Desktop VM on my MacBook Pro. (Quad Core i5, 2.3Ghz, 8GB RAM, Intel Iris Plus Graphics 1536MB) Those specs don't correlate exactly to a PC with the same exact numbers, but this laptop is 4 years old, and not high end. It seems I'm getting the same performance, CPU% higher - note that since it's a VM, some CPU% is required for the Mac OS - not a lot as I wasn't running anything else except this reply draft.

Not sure if that's of any help, but it's something to compare. For me - it's sort of what I would expect with that many projectiles in the air, but that's me and my setup.

Dave

Screen Shot 2022-03-07 at 6.48.44 AM.jpg (1.18 MiB) Viewed 1405 times

[thewood1]

The speed at which any app runs isn't all about CPU utilization. There are a lot of bottlenecks beyond the CPU. The bus, memory speed and load, GPU processing, hard drive data transfer, etc. Microsoft does not let every app have free reign to take over every resource on your PC.

If you take a brand new 12th series Intel i9 and put it in the architecture of a PC from 1995, you'll barely tickle the utilization of the CPU. There are tools out there to see where the bottlenecks are. But what you are seeing is similar to the issues in CMO around large numbers of ballistic missiles and other objects that require a lot of calculations. There are only so many calcs that can run at one time. And the CPU's resources aren't all allocated to doing theat. By accident and by design.

[thewood1]

I'll also point out a real-world example in CMO. I have an Op Brass Drum benchmark I run to monitor changes in performance. On my Intel i9-10900K at 5GHz, it runs fully time compressed around 80:1. But when a full attack arrives from the Iranian side with over 50 ASMs and 200 SAMs in the air, it drops to 40:1. On my Surface Book, it drops to 15:1 for a couple minutes. When the sim is running set to a time compression of 1:1, it stutters a little just for that short time.

There is only so much juice you can squeeze out of CPUs and their processing slots. The CPUs are doing a lot of other things so they have limits on each of those functions. A CPU might be running at 50% utilization, but utilizing 100% of its calculation capabilities. The i9 runs Op BD at around 20%, but the Book runs about 40%.

The short of it is, % CPU utilization is for the entire CPU tool set. CMO is probably using 100% of what is allocated to run its calculations, but that only makes up 30% of the raw capability of the given CPU.

[ultradave]

Good explanation. CPU utilization higher on mine, but performance seems about the same as his - and his with better specs. In both cases we're getting about as much out of it as is possible, with mine working a bit harder to do so.

Dave

[nukkxx5058]

Good explanation. CPU utilization higher on mine, but performance seems about the same as his - and his with better specs. In both cases we're getting about as much out of it as is possible, with mine working a bit harder to do so.

Dave

Thank you for running the file Dave. I appreciate And it comforts me that it's not apparently caused by my configuration. It seems that your RAM is nearly used in full but apparently not limiting your system.

In fact, the problem occurred on another scen that I'm currently developing and which is much bigger than this one with cca 3.000 units. But I was suspecting the missiles that can, under certain circumstances, be fired all at once like here. So I tried to recreate the situation in this smaller scen to isolate and test the sole missiles, and it really seems that these missiles are causing the slowdown. So I don't know if it could be a sort of bug or not ? Because after all, there are not so many units involved in this small scen, including the "large number" (it's all relative) of missiles. A few hundreds. I know they are lots of computation under the hood but sometime I read that people are running massive scenarios with 10+k units.

I also noticed that often, when guns are used, for example in Canary's Cage, when ships fire at land stuff on the islands at the end of the scenario, the game can become very laggy. When guns stops, it' all good again.

To me it seems linked with land combat (?).

So I don't know ...

But thanks again, at least it's apparently not a hardware issue on my side

[ultradave]

Lots of fast flying ballistic objects in the air all at once compared to absolute unit count in a scenario, where many units may be temporarily static or flying a set flight path and therefore not stressing the limit of calculations required? Even with a few hundreds of MLRS rockets that's a lot of ballistic calcs simultaneously, I would imagine.

But yes, it appears we are seeing pretty much the same thing, and my laptop didn't seem to be straining overmuch. The fan came on quietly but it usually does in CMO, at least intermittently.

Dave

[BDukes]

So I checked my power plan and min/max CPU usage is 100%, high performance.
It really puzzles me that my CPU is not working in full while the game is extremely laggy
Anybody else did run the test with the above save ?

Yes. Think everybody has confirmed it and done things to help move things forward. Great job! Ball is in somebody else's hands now

Mike

[westminster]

My computer is good for other games. With this game, I have the same problem, I just run game at 1 or 2 seconds per turn, when too much is happening in the battle.

[nukkxx5058]

In fact, I was wondering if upgrading for a faster CPU will help as my current CPU is already not used in full.
Because I was considering buying a top notch CPU but if the CPU is used at only 50% because of bottlenecks in the code, will it help ?

[thewood1]

Search my name and "benchmark" and you'll find several posts I did on this. In fact I did one just a couple months ago.

[thewood1]

In fact, I was wondering if upgrading for a faster CPU will help as my current CPU is already not used in full.
Because I was considering buying a top notch CPU but if the CPU is used at only 50% because of bottlenecks in the code, will it help ?

Did you even read my response from a couple days ago. The CPU will rarely ever be at 100% for any game.