Turning off hyper-threading had quite an impact on my P3Dv5

[simfan1983 185]

34 minutes ago, adam77 said:

Overclocking in Flight Simulation I would say is never recommended. You can in games where the overclock runs for short bursts of time, but over many hours of flying where the CPU would be pushed anyways, I would say you are getting the CPU to sprint for too long a period and over time, shorten its lifespan. I suppose with the way CPUs are released, it doesnt matter as you can always buy a new one when youve burnt through the current one. I just never find it worth it for the performance gain in the long run. 

I tend to disagree on this. P3D is unusual in that it places so much work on the CPU and on specific cores. XPlane and MSFS make better use of the GPU and I also believe use multi-threading so the clock speed is a bit less impactful on performance. Core clock speed makes a huge difference to the fps and smoothness in P3D. As long as you monitor temperatures and make sure they don't run consistently close to the thermal throttle zone then the silicon is designed to last for many years. I have always overclocked the CPU for P3D and I've never had a CPU fail. With gaming motherboards and utilities like Asus AiSuite you don't need to have a lot of knowledge to get a safe and stable overclock.

[d.tsakiris 418]

36 minutes ago, simfan1983 said:

XPlane and MSFS [...] use multi-threading

So does P3D.

[simfan1983 185]

5 minutes ago, d.tsakiris said:

So does P3D.

Not in the sense that tasks stick to individual cores. I'm not sure what the correct terminology is but the various tasks that P3D executes are only run on certain cores/LPs and they are not allocated dynamically. Various cores/LPs are used but the mainthread, renderthread and frameworker threads are allocated via the affinity mask lines in the p3d.cfg.

Edited September 24, 2022 by simfan1983

[Sethos 4,357]

2 hours ago, adam77 said:

Overclocking in Flight Simulation I would say is never recommended. You can in games where the overclock runs for short bursts of time, but over many hours of flying where the CPU would be pushed anyways, I would say you are getting the CPU to sprint for too long a period and over time, shorten its lifespan. I suppose with the way CPUs are released, it doesnt matter as you can always buy a new one when youve burnt through the current one. I just never find it worth it for the performance gain in the long run. 

Yeah, no chance a consumer is gonna burn through a CPU like that, ever. I've overclocked hundreds of CPUs and seen some of them run for a decade, just not happening. Everything you are saying just sounds like it comes from a place of reading too many fairy tales online. There's absolutely value and performance to gain from overclocking your CPU and not doing it on a modern CPU is just an absolute waste. It's leaving free performance on the table.  EDIT: Adding to that, a lot of modern CPUs have now built-in overclocking, that boosts based on thermals. 

Obviously you can kill a CPU quickly if you have no idea what you are doing and push a ton of voltage through it but a safe overclock, within limits, that'll last forever. 

Edited September 24, 2022 by Sethos

[chapstick 2,758]

18 minutes ago, Sethos said:

Yeah, no chance a consumer is gonna burn through a CPU like that, ever. I've overclocked hundreds of CPUs and seen some of them run for a decade, just not happening. Everything you are saying just sounds like it comes from a place of reading too many fairy tales online. There's absolutely value and performance to gain from overclocking your CPU and not doing it on a modern CPU is just an absolute waste. It's leaving free performance on the table. 

Obviously you can kill a CPU quickly if you have no idea what you are doing and push a ton of voltage through it but a safe overclock, within limits, that'll last forever. 

Exactly. This guy keeps posting incorrect advice and then asks people to follow him on Discord and YouTube for more "wisdom." No thanks.

[simfan1983 185]

For P3D It's also worth overclocking RAM (and possibly the GPU) by 10 to 15% especially if you don't have the latest and greatest hardware. Definitely check that the BIOS has an XMP profile enabled for the memory, as without that it doesn't even run at the advertised speed. Also make sure if you have two sticks of ram that they are operating in dual channel mode as sometimes people install them in the wrong slots where the mobo has 4 slots and you are using 2.

[Bob Scott 7,721]

23 hours ago, Ray Proudfoot said:

My i7-8086K is effectively the same CPU. Using the Asus utility available on their website - Ai Suite - I have managed to get the first 3 cores running at 5.0 and the remaining 3 at 4.9. There is a considerable uplift in performance.

I used to shy away from overclocking but this utility does it all for you. The only proviso is the need for an Asus mobo.

https://www.asus.com/support/FAQ/1012780/

Ray--the 8086K cannot clock the cores independently.  The way ASUS named it--"per core"--in their BIOS often leads folks to that misinterpretation. 

What you are actually doing is setting clock speeds based on the number of active cores...as you have described your settings, with 1, 2, or 3 active cores it will run at 5.0 GHz, with 4, 5, or 6 cores active it will run at 4.9 GHz.  But in any case, the cores all run together using a common clock signal.

 

[Ray Proudfoot 8,964]

34 minutes ago, Bob Scott said:

Ray--the 8086K cannot clock the cores independently.  The way ASUS named it--"per core"--in their BIOS often leads folks to that misinterpretation. 

What you are actually doing is setting clock speeds based on the number of active cores...as you have described your settings, with 1, 2, or 3 active cores it will run at 5.0 GHz, with 4, 5, or 6 cores active it will run at 4.9 GHz.  But in any case, the cores all run together using a common clock signal.

 

I didn’t do anything manually Bob. I just left the software to its own devices. I have HT enabled so that gives me 12 virtual processors. I just read the values shown by AI Suite.

So it looks like all 6 are running at 4.9Ghz. That’s certainly a nice boost from the first running at 5 with the rest at 4.5.

[d.tsakiris 418]

7 hours ago, simfan1983 said:

Not in the sense that tasks stick to individual cores. I'm not sure what the correct terminology is but the various tasks that P3D executes are only run on certain cores/LPs and they are not allocated dynamically. Various cores/LPs are used but the mainthread, renderthread and frameworker threads are allocated via the affinity mask lines in the p3d.cfg.

Not sure I understood you correctly, but as far as I know, P3D assigns one thread to every physical core. That assignment is done on start-up and not changed by P3D dynamically, I believe. The last time I checked, it didn't assign to the logical cores by default - that might have changed in the meantime, but I doubt it. One can change that default assignment by adding the according lines in the prepar3d.cfg, and one can change in during run-time with external programs.

[Luke 782]

55 minutes ago, d.tsakiris said:

Not sure I understood you correctly, but as far as I know, P3D assigns one thread to every physical core.

No, the Windows scheduler assigns threads to cores. All the affinity masks (and other software, like Process Lasso) do is tell the Scheduler what potential cores to limit things to but at the end of the day P3D is just another Windows app.

Cheers

[d.tsakiris 418]

How does the AM in the config file work in that case? One can define precisely which type of thread executes on which core. Wouldn't Windows practically always mix that up?

[Bob Scott 7,721]

54 minutes ago, d.tsakiris said:

How does the AM in the config file work in that case? One can define precisely which type of thread executes on which core. Wouldn't Windows practically always mix that up?

In Windows, both processes (e.g. Prepar3D.exe) and their individual threads can each have their own processor affinity mask, and also a preferred processor affinity.  The processor affinity mask essentially tells the OS what processors not to use (not cores, but processors, to include virtual processors in an HT/SMT environment).  An affinity mask is exclusionary--it "masks off" specific processors, leaving the rest available to be assigned.  When a preferred processor affinity is specified, it tells the OS to give a higher priority to the requesting process/thread than to other tasks not also coded with a preference for that specific processor.

Ultimately, the OS scheduler decides, based on the task affinities, the load distribution, and a complex mix of other factors.  That said, on a many-processor machine with no other high-demand processes running, you can generally expect the processor requests made by the sim and its threads via their affinity masks to be honored by the OS, since there isn't likely to be anything else competing for those specific resources that can't be moved to another processor.  The latest versions of P3D do allow separate affinities to be specified for three types of core processes.  I would assume that P3D probably takes the config file parameters and forms preferred processor affinities for the main, render, and frameworker threads as well as a more general process affinity mask for P3D itself.  Barring some other high-workload program running at the time P3D is started, Windows will almost always honor P3D's affinity preferences, especially on a modern 6+ core CPU.

[cowpatz 243]

Whoever would have thought that learning Latin would be easier than tuning a flight simulator........

[TurboKen 221]

On 9/23/2022 at 12:51 PM, simfan1983 said:

No Sir, I was flying with someone else who was streaming on Twitch and just had a short break for food. It was actually very rewarding - Hong Kong to Zurich in a Swiss 777 flying an IVAO tour flight. I love long hauls, especially when P3D doesn't CTD!

Wow, congratulations. I hope your PC has good cooling for these long trips.