November 26 - did a nice flight around SE San Diego county using KSEE (El Cajon/Gillespie) as departure and arrival.  Never got more than 5 miles from KSEE in Areobat 152.  Frame Rate stayed above 23 (Dev Mode or 45 or so in Frame Gen mode) and CPU/GPU stayed around 50% to 70%.  The network traffic for the sim stayed around 1.0 to 3.0 Mb/sec.  Rolling cache is 16GB and was being updated.  Frame time was about 28 - 32ms for CPU and 28 - 30 for GPU.  I landed and shut the sim down normally. 

An hour later restarted the sim with exactly the same stuff and flew exactly the same pattern.  Frame rate never got above 4 in dev mode and less than 9 in FG mode.  Only one of the 8-processors was above 2% busy and that was only about 10%.  The GPU was less than 40% busy.  The frame times for the CPU and GPU were almost identical to the prior flight.

The big difference was that Network traffic was consistently above 10 Mb/sec and frequently above 20 Mb/sec - or about 5 to 10 times the traffic as the prior session.  

I thought the rolling cache was to be used so that if I flew in the same locale - there would be no need to download data. I did fly almost the same pattern at the same distances as the prior sesson. 

But, at least in this case, the sim downloaded a great deal more data.  It is not clear that the downloading was the cause of the low frame rate but I do know the CPU was hardly being used and my 1 GB/sec connection was running smoothly.

This is the 2nd time I have seen this phenomenon - very high network traffic rates, very low CPU utilization, and frame times at normal responsive levels. 

Edited November 26, 20241 yr by TacomaSailor

It's not surprising the CPU is being used less. It's using all the cores now, supposedly, which would distribute the load and lower the usage. I'm not even testing for optimizing graphics/framerates at this point, until a few more hotfixes are released and the sim itself gets more optimized.

 

Yea it seems too early to test these things -- and I am just trying to figure out the sim!

I am not sure the rolling cache is even being used yet, is it?

1 hour ago, eslader said:

It's not surprising the CPU is being used less. It's using all the cores now, supposedly, which would distribute the load and lower the usage. 

Some tasks done in 2020 on the single-thread performance-dependent main thread are being offloaded to other threads in 2024 but there is a whole lot more total processing happening as well hence the 4000x polygon density and more.  This fits with current anecdote that indeed in 2024 the CPU runs hotter than it does 2020.  

2 hours ago, eslader said:

It's not surprising the CPU is being used less. It's using all the cores now, supposedly, which would distribute the load and lower the usage. I'm not even testing for optimizing graphics/framerates at this point, until a few more hotfixes are released and the sim itself gets more optimized.

 

That's not how CPU usage works.  If you move stuff from one core and distribute it to others, it's still using the same amount of CPU, just less usage per individual core.  

Yes, I wasn't precise in my wording. When something is only using one core, one of the cores' usage can spike to 100% while the others are loping along at idle. Most of the time, this gets reported by users as "my CPU is at 100%."

When you distribute the load across multiple cores, it lowers the per-core usage, which means the user stops thinking the CPU is at 100%.

19 hours ago, eslader said:

It's not surprising the CPU is being used less. It's using all the cores now, supposedly, which would distribute the load and lower the usage. I'm not even testing for optimizing graphics/framerates at this point, until a few more hotfixes are released and the sim itself gets more optimized.

 

When I was seeing 25 FPS (Dev Mode) one processor was always more than 80% busy, three or four were 30% busy, and the remaining cores were 10% or so.   That means 230% of 800% (eight cores at 100%) cpu cycles were consumed.  In the low frame rate situation no more than 20% of 800% of the cycles were used.  Additionally, and deeper in the weeds of system measurements,  Flightsim2024.exe had about 50 threads created. 

During the low FPS situation: The three busiest threads (each about 5 to 10% busy) were in a wait state most of the time.   About 20 threads total were using cpu cycles but most were only busy less than 1% of the time.

I have seen no indication that 2024 multi-thread cpu usage is spread across any more threads than 2020.  The three busiest 2024 threads, when flying level at 5,000 AGL and 150 knots, account for the totality of cpu cycle consumption in 2024 just as they do in 2020.  2024 does create more threads than did 2020 but almost all the additional threads are unused except during loading.  This situation may change as the devs learn more about the behavior of the sim code in thousands of user systems. 

Sorry to be all geeky but this was my professional life for 30+ years. 

20 hours ago, TacomaSailor said:

I have seen no indication that 2024 multi-thread cpu usage is spread across any more threads than 2020. 

Well... That's disappointing. Hopefully that's just a bug off since sort and not an asobo-exaggerated feature promise.