Dear All,

 

ventubo tools gives me a setting of 1344 for my 6 cores (HT on so 12 total threads). What is the setting that you recommend from your experience?

 

regards

 

Fulcrum

I have a hex core as well and I use 14. I find certain stutters are worse using 62 which I think is supposed to be the best for hex cores.

try 63 as that is what I have for my unlocked 960t, but I prefer to keep the Affinity through the Task Manager.

I have a hex core as well and I use 14. I find certain stutters are worse using 62 which I think is supposed to be the best for hex cores.

 

Have you tried 56?

You'll have to play around with the settings until you find the one that works best with your rig. I can say that FSX will use as many cores as it can find, but it doesn't usually like hyperthreading - usually leads to stutters. I'm actually not too sure about the 1344 suggestion - doesn't make a lot of sense. This would only be enabling the last 3 physical cores which kind of leaves at least two physical cores (core 2 and 4) not being effectively used.

 

I use Affinitymask=1364. This ensures only the physical cores are used, ie no hyperthreading and frees up the first core which still runs fiber scheduling (which is always fixed to core 0) and any other apps that might be running in the background. Seems to give me the most "smoothness" and performance for my i7-980x.

 

If you wanted to try running with logical cores, you could try Affinitymask = 4092. This will enable the last 10 cores, and once again leave the first core (physical and logical) free for fibers and other processes.

 

Good luck in your testing and let us know what works best.

I've found out that the affinitymask tweak decreased performance on my computer slightly. Unless you run some very heavy single core software simultaniously with FSX there is no need for the tweak.

 

FSX works fine with hyperthreding, but can make the CPU run slightly hotter, especially if you overclock it.

DannyH73,

 

Are you sure 1364 is for a Hex ?

DannyH73,

 

Are you sure 1364 is for a Hex ?

 

yep - hex core, 12 threads (6 physical and 6 logical) - leaves core 0 free and uses cores 2, 4, 6, 8 and 10 - stopping any logical cores from being used.

 

Core

0 1 (first physical core)

1 2 (first logical core)

2 4 (2nd physical core)

3 8 (2nd logical core)

4 16 (3rd physical ...

5 32

6 64

7 128

8 256

9 512

10 1024

11 2048

 

So: 4 + 16 + 64 + 256 + 1024 = 1364 (the last 5 physical cores of a hex core with HT enabled)

 

The above is a good table to work out what values you want to use. Makes the maths quite easy too - just add the values together of the cores you want to enable

Just to add - if you had a hex core without hyperthreading you would have a smaller table:

 

Core

0 1 (first physical core)

1 2 (second physical core)

2 4 (third physical core ...

3 8

4 16

5 32

 

So a hex core without hyperthreading, to use the last 5 cores and keep Core0 (the first core) free would be: 2+4+8+16+32 = 62

My settings for the i7 980 [without X] is 4085 which means that the first two HT cores are turned off.

Read this back wards: 111111110101. Works perfectly for me. In the early days of FS I used to have a very fast CPU with HT, the first one made. That helped in FS 2000 / 2002 which iff I was to believe even some "professionals" would not be possible at all.

Personally I think the usage of HT in FSX is based on misconceptions about what HT does Advice to read about this on the Intel site, http://software.inte...ght-simulator-x

[note that there is talk about threads, not just cores. HT is about threads]

But there are also some animations on how HT works somewhere at the Intel site.

HT is an option for CPU cores to let threads pass in a way it makes better use of a physical core. That is not being arranged by FSX or any other program but the Intel chipset, CPU and drivers.

After fiddling around with the settings [which might be different for any of you] I found that by turning the first two HT cores off I could avoid a reoccurring "collision" between threads.

Apparently there where threads waiting for eternity to let the other pass through the CPU.

Leaving the other HT cores on, gives other programs, background services etc, some room to have their threads passing through the CPU cores.

It's a matter of test and try what works the best for you. Use the scientific calculator of Win 7 / Vista and set it to binary. Remember that the cores are read backwards, fill in any combination you would like to test and try. 1111 1111 1111 [all cores in the 980] is read, after switching to decimal as: 4059

1365 = no HT, but all other cores on [0101 0101 0101 watch the first 0 not appearing when entering it in the bin function of the calculator= 101 0101 0101]

If you, like some, believe, that HT doesn't work at all with "X" then why not turn it off in the PC's BIOS?

That all been said, the biggest problem of "X" isn't CPU usage, but the addressing of memory, I hope one day we will see a neat 64 bit P3D…..

Why do you insist on using Hyperthreading when it is not used by FSX?

 

AF=62 is correct for HT off. 1364 with it on.

 

Dave

I insist in using HT because Windows 7 likes it for one and some of the other apps of my machine like it, so it stays on in the BIOS. There is a misconception of what HT does. HT is about threads passing thru a cpu. While running FSX there's a lot more going then just X. 4085 works perfect for me and I'm using this for more then 2 years now flying about 25 flights a month in all sort of flights. longhaul, short hops, IFR [PMDG] and VFR. The only thing i did with the BIOS is making the machine run at 4,2 GHz.

Friends,

 

Thanks a looooot for all your comments and insights. I did testing on my system (asus P9X79 i7 3930K OC to 4.00 Ghz HT on) , testing all affinity mask setting with the same plane (NGX), at the same place (LSZH runway 28 aerosoft scenery) at the same time (dawn) with the same weather (thunderstorm). Strangely, 14 seems to be the best setting ( i tried all the above suggestions). Maybe I am doing something wrong. Will report back

 

Best

 

Fulcrum