Recapping:

The first task on the first core of P3D is monolithic and is mostly responsible for fps capacity in  the simulator, the other cores perform background tasks in parallel such as collecting scenery data. So we need the maximum performance in the first core and enough other cores to process the background tasks efficiently. If we limit the fps so that the first task does not quite consume 100% of the core then we have overhead in that core to allow for increases in load along the route. If the first core reaches 100% it can't increase throughput to maintain fps and the fps will drop.

HT enabled increases processor utilization and does more work overall, and by doing that it get's a little warmer, but it won't improve fps by more than one or two frames at 30fps, it can load scenery faster and pass that information to the main task more efficiently. We can only save heat by disabling HT. In an overclocked system the overclock will be set down the heat curve slightly to accommodate an HT enabled setup, or with HT disabled the overclock can go a little higher.

We can't improve performance by turning off HT, we can only decrease utilization and heat. Those claiming performance increases with HT disabled did not have appropriate Affinity Masks with their HT enabled P3D setup, otherwise it is only a way to lose performance.

If we don't apply an appropriate Affinity Mask to P3D with HT enabled the first core will share the first task with the second task which subtracts performance available to the first task.

In any case, HT enabled or not, allowing other processes to use throughput of the first task will also subtract performance available to the first task. A little more performance can be gained by corralling other exe apps that run alongside the simulator onto cores other than the first so that it is ensured that they don't consume throughput of the main task. In a complex system the jobscheduler can't be sure to locate processes away from the main P3D task, we can help it do a better job with managing affinity ourselves.

CPUs with very high core counts might require that we actually limit the number of cores used by P3D so that when the aircraft arrives over new scenery the total hit of all the cores collecting that scenery is not overwhelming the system. The system can only handle a finite bandwidth no matter how many cores in the system.

 

Edited July 27, 20214 yr by SteveW

27 minutes ago, Ray Proudfoot said:

Back with HT on now but I did increase the core up to 4.7 from 4.6. Insignificant I know but the long term plan is to try to get to 5.0.

One of the keys to a successful overclock is to work out the lowest CPU voltage you need to run stable. One approach to find this is to use the auto voltage setting at your desired frequency and see what the BIOS decides is needed and work down from there in small steps. My BIOS also has 'optimistic' and 'cautious' voltage settings so I tried the optimistic setting and had to bump it up a tiny bit as it wasn't fully stable. I also use Intel SpeedStep in the BIOS to drop the voltage and frequency when the processor is under lower load, as this keeps the average temps much lower.

10 minutes ago, simfan1983 said:

One of the keys to a successful overclock is to work out the lowest CPU voltage you need to run stable. One approach to find this is to use the auto voltage setting at your desired frequency and see what the BIOS decides is needed and work down from there in small steps. My BIOS also has 'optimistic' and 'cautious' voltage settings so I tried the optimistic setting and had to bump it up a tiny bit as it wasn't fully stable. I also use Intel SpeedStep in the BIOS to drop the voltage and frequency when the processor is under lower load, as this keeps the average temps much lower.

The main reason I bought an assembled PC was that overclocking would be done by people who knew what they’re doing. Plus I get an overall warranty missing if I build it myself.

I’ve always had an inbuilt fear of the BIOS even though these days there are tools to make tweaking easier. Voltage is something I’ve never touched simply because I don’t know what is safe and what isn’t. The tiny steps I’ll take should be safe but on the first BSOD I’ll backtrack.

The best way to get improved fps is to move the key sliders to the left as I discovered this morning. I’d much rather see another 30 Ai than a few more buildings.

Temps have never been an issue for me. In the cooler months the room remains unheated. Those living in Florida aren’t quite as lucky as us Brits. 😉

@SteveW, excellent write-up. 👍

I also have a pre-built pc (my second from Quiet pc) but it is designed to be overclocked and as long as you are sensible it doesn't void my warranty. These would be the steps I would recommend before attempting to change the voltages:

- Take a backup of the system drive in system image format (I use the Windows 7 Backup  that is still present in Windows 10). If you end up with any file corruption due to a blue screen you can restore the whole drive from the backup in extremis). It's unlikely that things will go that wrong but it is better to be safe than sorry.

- save (and  write down) the key BIOS settings so you can go back to them, as well as trying default settings again in extremis

- make sure you have an up to date BIOS - the motherboard manufacturer's website will tell you what the latest stable version is. If you are going to upgrade the BIOS make sure you know how to clear CMOS in case it doesn't work. Many modern motherboards have switches to do this but older ones require you to short two jumpers.

- Use CPU-Z and CoreTemp or similar utilities to keep trach of frequencies and temps.

- only change one thing at a time

- go in small steps and stress test at each stage.

If you use Google to search for your motherboard and overclock and the desired frequency there are often lots of forum posts from users who have been there before and offer useful advice.

If you can get to 4.8 without too much effort and overclock the memory by say 15% I think you will notice a difference.

 

Edited July 27, 20214 yr by simfan1983

@simfan1983, I know you mean well but I really don’t want to get into this. I have three saved profiles for previous changes I can easily revert to should it be necessary. So far, small incremental increases in clock speed have been problem free.

If you ever want to learn how to fly Concorde then I’m definitely up for that. 😁

18 minutes ago, Ray Proudfoot said:

I’ve always had an inbuilt fear of the BIOS even though these days there are tools to make tweaking easier. Voltage is something I’ve never touched simply because I don’t know what is safe and what isn’t. The tiny steps I’ll take should be safe but on the first BSOD I’ll backtrack.

Research, research, research. Most BIOS settings are quite arcane and only necessary for extreme tweakers. I stick to memory XMP profile, CPU core freqs, CPU voltage (1.4max) and cache freq.  With sufficient cooling everything else just becomes noise really. That gets me to 5.1Ghz across 10 cores at low temps. Could I o/c the memory a bit more? Probably but haven't invested the time when the main tweaks give me great performance.

13 minutes ago, Ray Proudfoot said:

@simfan1983, I know you mean well but I really don’t want to get into this. I have three saved profiles for previous changes I can easily revert to should it be necessary. So far, small incremental increases in clock speed have been problem free.

If you ever want to learn how to fly Concorde then I’m definitely up for that. 😁

No worries, hopefully it will be helpful for other readers. If FSLabs do manage to get Concorde out for P3D I will be fighting you to the front of the queue - definitely my favourite real world aircraft!

12 minutes ago, kevinfirth said:

Research, research, research. Most BIOS settings are quite arcane

But Kevin, the interest has to be there and for me I have zero interest in the BIOS. I’d rather spend my time flying than all this piddling around with settings. Reducing one slider by one notch had improved things sufficiently for me.

Same applies to you regarding Concorde. 😉

26 minutes ago, Rob_Ainscough said:

Ray, you sound like Pete, he loves having billions of AI flying around (ok maybe not Billions, Millions) ... AI will put a lot of load on core 0 ... which is apparent by your 100% pegged core 0 image.  I'd recommend you NOT allow Core 0 to stay at 100% all the time, either reduce AI or drop CPU intensive settings down a notch.  Having the CPU pegged at 100% all the time is going to trigger other issues with scenery loading.  I'm assuming you aren't running an artificial FPS limiter like RTSS or NCP?

Especially when I do a world tour and see all those fantastic liveries not seen in Europe or the US. I have lowered one key autogen setting as you have seen. I agree that core 0 at 99% would be ideal. The problem is the weather. What works with a few fluffy cumulus doesn’t with 8/8 stratus and rain.

No, fps is set naturally with my monitor set to 30Hz and VSync enabled. Unlimited is set in P3D.

30 minutes ago, Rob_Ainscough said:

With HT off, you should be able to run 200-400Mhz more.  But make sure your memory is stable first, run Prime95 with and without AVX test, if you are failing on AVX then offset it in BIOS.  From what I've seen the 8086K can run 5.3Ghz AVX 1 at 1.345v using GSkill RAM 3200Mhz CL16 (which is middle of the road RAM).

Most of that is Greek to me Rob. 😁 I have 3000 RAM which was cutting edge 3 years ago. As I said earlier the interest has to be there and it just isn’t. I’m currently running 4.7 with HT on.

Yes, I accept I started this topic with a weird problem but it’s not surfaced since. Core 0 remains at or close to 100% especially around London airports. I suspect it might have been caused by changing AF on-the-fly. Not something I tend to do.

Point taken about the time taken to find an acceptable overclock by builders. An increase from 4.6 to 5.2 is a 13% increase. So fps goes from 25 to 28. Is that worth the extra heat generated maybe shortening the life of the CPU? Hmmm.

I started investigating overclocking as something to do during long cruises as it can be quite interesting learning what all the settings do, but I have a lot of sympathy for those who don't want to fiddle around in the BIOS. The one thing I would probably check is that the memory is running at the advertised speed. If it's underclocked this is a really easy fix that can add 20% performance by changing one setting. Windows Task Manager - Performance - Memory tab will tell you your RAM speed in MHz, compare that to the headline figure when you bought it. I have little doubt that Ray's system has been set up properly so this post is mainly for others following this thread.

Sorry to hijack this Ray or at least to post my own issue that may be related. I've struggled with FPS for a while, I sometimes get it stable but then things seem to degrade or I get a lot of stutters. A lot of it started when I got a G-Sync monitor and I still have to turn G-Sync off because the stutters are unbearable. It isn't related to overclocking or anything else either as my other games are absolutely fine.

I've just loaded up the TFDI 717, cold and dark at a stock airport, FPS is bouncing around 10-15% below the frame limit, it gets worse if I take the jet up and accelerate. In my Task Manager 'System' and 'Desktop Window Manager' are using nearly 30% of my GPU and if I close Prepar3D, they stop, it's bizarre!

I'm very tempted to do a full Windows reinstall as I haven't been happy with Prepar3D for a month or so now. Even MSFS 2020 is almost better which is ridiculous.

Edited July 27, 20214 yr by G MIDY

8 hours ago, Rob_Ainscough said:

You might need to enable or disable GPU acceleration support form the TFDi 717 configuration tool.

Cheers, Rob.

Thanks Rob, I did give that a go, GPU accel was already enabled so I turned it off but it seems worse and the Desktop Window Manager stuff is still running.

Below is the exact same scenario with the PMDG NGXU loaded, FPS has improved but it's still stuttering. The GPU and CPU are barely used and only by other applications

I'm pretty convinced that MS has broken something in the recent updates which has affected P3D, maybe Ray is having the exact same problem too.

 

Edited July 28, 20214 yr by G MIDY

Lawrence, without knowing your CPU, GPU, AM setting, resolution and how your controlling fps it’s hard to advise.

A screenshot of the performance tab would be helpful plus your hardware. Putting it in your signature is always best. You should not be having any issues at a default airport.

Ray, overclocking is made much easier by programs like MSI Afterburner [NO! AI Suite 3!] without venturing into the BIOS.  On my setup I have 3 profiles saved from MSI Afterburner and can change back to any of those with a few of keypresses. It doesn't handle memory overclocking, but it can do all the rest and it includes a facility to automatically find the highest overclock which remains stable (it has its own tests built in).

Don't be put off by the "MSI" part -- it works with all modern motherboards.

Like you, I don't like venturing into the BIOS. I left BIOS settings up to Rob when he built my PC. I find it near impossible in any case because the screen on which the BIOS appears is always the curved one and I really cannot handle the mouse on that projection!

Have a look at MSI Afterburner, see what you think. Even if you don't overclock with it, it shows a lot of useful (adjustable) data.

Pete

 

 

Edited July 28, 20214 yr by Pete Dowson

Hi Pete,

I have used MSI Afterburner but in combination with RTSS for on-screen monitoring of CPU, GPU etc.

I'm wondering how much more fps can be improved even if I clock it to 5.1 over it's current 4.7. The i7-8086K is different in that core 0 is turbo-boosted over the remaining cores and how that would be handled with MSI I'm unsure.

I'll bear it in mind but after several days of testing and tweaking I just need a bit of a rest and some flying.