3 hours ago, Jim Young said:

I am totally against the Affinity Mask tweak unless you have a system prior to Sandy Bridge (i7 2600K).

 

Actually, my Skylake 6700k (4 cores, HT on, OC 4.5 Ghz) runs best (meaning, no noticeable stutters or long frames) with Affinity Mask=245 or 85; by contrast, with default setting (i.e. no affinity mask in cfg) I experienced fairly significant stutters.  This is quite reproducible on my system.

Whether or not one needs to use the affinity mask setting is highly dependent on one's specific hardware and software environment.  On my system, allowing P3D to run with two threads simultaneously on cores 0 and 1 while also hyper-threading does not work well, and the observations are consistent with what was discussed in the reference thread posted by Alan. I choose to keep hyper-threading on because my sim computer is also used for other applications where HT is a clear benefit.

 

 

That's great!  Glad it works for you.  It does not for me.  I see no stuttering, long pauses with HT on.  No tweaks.  But I have a 7700K.  I have most of my settings set to max and have no problems whatsoever with stutters but then I have a more powerful CPU and MB and GPU.

I have no concern with experienced persons like you using the tweak or any tweak but we have a lot of members who are not that familiar with computers and will add a tweak just because someone else has a tweak and the tweak settings are much different on their system than others.  They then have unexplained crashes and other anomalies. 

Personally I will not use the tweak as I have seen too many issues with it over the years. 

Haven't read all posts so sorry if repeating but my suggestion would be :

Disable HT to allow your CPU to run cooler meaning you'll be able to overclock it higher at lower voltage and stay away from any tweaks including AM tweaks.

HT on AM=245 with VSYNC and unlimited smooth as silk

Have a look at this discussion, I show how v4 utilises six LPs to split out the rendering section leanest with only four cores:

So if we only have four cores available 245 unmasks six logical processors and allows the sim to split out its parts to the leanest rendering. Also since we only have four cores those doubled up jobs show how HT enabled provides the mechanism to improve on maximum core throughput.

Like saying we need not worry about checking the oil, especially if we fly faster. If we give P3D a rubbish AM it will actually still work OK, any problems reported will be from other finger trouble.

HT and AM - these minor technical details are a necessary evil right now especially with many-core CPUs arriving. Most of us want a good P3D PC and we won't be pushing frequency limits. If it has an overclock then it will be moderated to accommodate HT which will more than regain the lost cycles to a few MHz. Eight core is becoming abundant, six core can OC higher, but they still only use two cores for rendering

could you suggest between AM=250 and 254 on quadcore with HT on. The light second rendering task is shared with a fifth loading task on a core with its two LPs in the latter. Can that improve the throughput or better to stick with 250?

Speaking of new multi-cores CPUs coming I watched this clip on YouTube yesterday.

I don't know anything about this guy but what he says in this video will at least make me think twice about upgrading my current 6600K.

I am running my [email protected], HT on, no AF -> runs perfect.

I get stutterts with any AFmask setting.

15 minutes ago, swiesma said:

I am running my [email protected], HT on, no AF -> runs perfect.

I get stutterts with any AFmask setting.

Have you tried what stable OC you can achieve with HT OFF?

If not I would certainly give it a try if I was in your shoes. Probably you could go to 4.5 or even higher still getting the same temps and possibly also by using lower voltage and at the same time get more FPS out of the sim and still perfectly smooth. This is exactly how I'm running my 6700K accompanied by a 980Ti with perfect results in VR using a pair of Oculus Rift glasses and the FlyInside software. In my experience that is equally taxing to the system as running at high settings at 4K.

Another thing I learned the hard way with having HT on was it will make P3D consume loads more VAS. I was in a situation where I had to reinstall my PC after a disaster with a misbehaving add-on and after doing this I kept running into VAS issues I haven't had before the reinstall.

No matter what I tried I kept running out of VAS using the exact same add-ons and settings as I was before the re-installation plus my CPU ran much hotter than it usually would. Eventually I realized somehow HT had been enabled and I still don't understand how. Anyway I switched it back OFF and all my VAS issues disappeared and my temps were back to normal and I haven't had a single issue since.

Obviously this might not be very interesting from a VAS perspective now with P3Dv4 but thought I would still mention it for anyone else still on P3Dv3 like me waiting for a number of specific add-ons to become available before upgrading to P3Dv4.

32 minutes ago, WebMaximus said:

Have you tried what stable OC you can achieve with HT OFF?

With HT off I get to about 4.6, with HT on I get 4.4 stable but with a bit higher temps.

 

That doesnt make a difference in FPS to me. So I stay with HT on :-) Why would I make an i5 out of my i7? :-) 

I use the PC for other stuff too. But I think it differes a lot, even like it was said above which addons you use besides P3D.... I think there is no golden rule for this.

7 minutes ago, swiesma said:

With HT off I get to about 4.6, with HT on I get 4.4 stable but with a bit higher temps.

 

That doesnt make a difference in FPS to me. So I stay with HT on :-) Why would I make an i5 out of my i7? :-) 

I use the PC for other stuff too. But I think it differes a lot, even like it was said above which addons you use besides P3D.... I think there is no golden rule for this.

Fair enough and what you say is of course true - if using other applications as well where having HT enabled will have a positive effect on those other applications you should of course keep it enabled. I was looking at it from a pure FS perspective and what I've experienced so far in regards of HT ON vs OFF.

The reason I've chosen to make an i5 out of my i7 is I prefer lower temps and yet the same performance or even better ;-) but then again I mainly use my PC for P3D.

The reason i stayed with HT off on my 3930K was overall smoothness along with a 30hz refresh rate on my monitor. I did tests using FRAPS and the average graphs and long frames told the whole story. With HT on the graphs were way more random and spikey whereas with HT off the graph was smoother and consistent and this was noticeable in the sim itself.

This was using the same overclock of 4.4ghz.

Guys - very amusing reading all about how HT and AMs cause problems.

 

A) there's no such thing as "no AM"

four core no AM=15

six core no AM=63

eight core no AM=255

 

B) HT on or HT off makes absolutely no difference to the sim

four core HT off no AM=1111 HT on AM=85=01,01,01,01 sim runs entirely the same as it does not know there are eight processors sees the same HT Off four cores.

 

given A and B:

Turning HT on giving problems simply put means you didn't get it right

Using any appropriate AM and getting problems simply put means you didn't get it right.

 

 

 

Another interesting video talking about PCI lanes, SLI and multi-core scaling and how it performs IRL vs in the market material.