LOD_RADIUS=15 but it's NOT about distance

[Pete Dowson 558]

Let's try again...why do people choose to use HT as it relates to FSX?

 

Well, there are probably different reasons for HT being enabled, varying for different folks. Let's see:

 

1)  Ready-made PCs with HT type processors will come with HT already enabled. Many folks don't change it perhaps because they don't know how or simply don't want to mess with BIOS settings,

 

2)  Some folks do actually use their computers for things other than FS, and many other programs probably make better use of HT than FS, After all, I don't think Intel implemented it just to be a nuisance, it has uses.

 

3)  Having HT enabled doesn't make FS run any worse, and if the PC is not overclocked having HT enabled doesn't really make it run particularly hotter. Folks who want to extract the max clock rates out of their PC tend to disable HT to enable higher clocks without so much increase in temperatures.

 

There are probably other reasons. I don't really know why you are asking the question. I assume you've disabled it or don't have a processor with HT, so what is your reason?

 

Regards

Pete

[Noel 4,573]

 

 

I don't really know why you are asking the question.

 

Because it isn't clear to me after reading various threads and comments whether or not there might be 'performance', for example texture loading/frame rate/IQ/smoothness benefits from enabling HT.  Teasing thru your various comments I have conclude your opinion, or you are agreeing w/ DAL's opinion, is there is no performance benefit per se w/ regard to FSX.  Thank you for your opinion.

[Pete Dowson 558]

Because it isn't clear to me after reading various threads and comments whether or not there might be 'performance', for example texture loading/frame rate/IQ/smoothness benefits from enabling HT.  Teasing thru your various comments I have conclude your opinion, or you are agreeing w/ DAL's opinion, is there is no performance benefit per se w/ regard to FSX.  Thank you for your opinion.

 

I really don't have an "opinion" on this, but I understood from many things that I've read that the consensus is that there is actually a performance penalty if FSX is allowed to use the "HT" virtual cores rather than the "real cores". This is why the Affinity Mask folks quote for HT-enabled PCs have zeroes in the bits said to be those representing those virtual cores, so telling FSX not to use them.

 

Personally I've always either used a processor without hyperthreading, like the i5-2500K, or, as now, turned HT off in the BIOS with my i7-4770K. I have most certainly never seen any advantage of having HT enabled for FSX, and since I want to achieve the highest stable clock rate I can with my new PC I have HT off because I have also read that the temperature can be controlled a little easier without it.

 

And that's really all I can say on the matter. I only contributed to try to clarify the bits arrangements in the Affinity Mask values, not to argue for or against anything.

 

Regards

Pete

[padolamap 7]

What is the theoretical basis of higher temperature? People here say higher temps, but I don't see it when I run HT enabled and 4089 which distributes work in all 12 threads. The only way I could see higher temps happening is if:

 

1. More work being done or

2. The work being done is done less efficiently, hence more watts are required to do the same tasks.

 

Also if you will, what are you trying to accomplish w/ AM of 1364?

I did this test using coretemp and that made the difference in temperature, if you force one will have the temperature of one but if you force every one will have the temperature multiplied by each processor, I repeat the processor load in only ditribulle fsx load running then once distribulle not all do the same job, just put the simulator in windowed mode and see on your cpu rendimeinto vera as all do the same and you can see also they do not get fps gain

[Pete Dowson 558]

BTW, Noel, I ought to correct this, whiich I just noticed:

 

... when I run HT enabled and 4089 which distributes work in all 12 threads.

 

The number 4089 is 0xFF9, or binary 1111 1111 1001, so it doesn't use all 12 threads, it omits the "virtual" one associated with core0 and the real core1. A rather odd choice of omissions really.

 

If you simply want FSX left to use them all as it wishes, you either need 4095 (0xFFF = binary 111111111111), or, easier, simply remove the AffinityMask parameter altogether, because its only function really is to be restrictive.

 

Regards

Pete

[OldMaintChief 7]

AM Summary

 

With no AM entry, all main cores are used, and no HT cores (same as AM=15). The purpose of the tweek is to tell FSX to ignore core 0 and move to core 1 and put the Terrain and Textures on cores 2 and 3. Windows will still use core 0. If HT is on, AM=254 will cause FSX to also use the 4 HT virtual cores for T/T. This setting will cause the cpu temp to rise. Mine goes from 62C to 75C. The tweek should make FSX smoother without affecting fps very much. Any other numbers turn off cores for no reason.

 

Quad core without HT, First core free and last 3 on would be: = 14. All four on = 15.

 

HT off = 14 (4 main cores on minus core 0) Code: 0000 1110

 

Quad core with HT, First core free and last 3 on (no virtual cores) would be: = 84.
All eight on = 255.

 

HT on = 84 (4 main cores on minus core 0) Code: 0101 0100

 

HT on = 254 (all 8 cores on minus core 0) (higher cpu temp) Code: 1111 1110

 

Hex core without HT, First core free and last 5 on would be: = 62. All six on = 63.

 

HT OFF = 62 (6 main cores on minus core 0) Code: 0011 1110

 

Hex core with HT, First core free and last 5 on (no virtual cores) would be: = 1364.

All twelve on = 4095.

 

HT on = 1364 (6 main cores on minus core 0) Code: 0101 0101 0100

 

HT on = 4094 (all 12 cores on minus core 0) (higher cpu temp) Code: 1111 1111 1110

 

Dave

[Bert Pieke 7,605]

Not to put too fine a point on it, but 4094 would put the main FSX load on the virtual half of Core0 - an odd choice..

 

In that case, 4092 or 4084 would make more sense ^_^

 

4084:    1111 1111 0100

 

Core0 free for OS stuff.

 

FSX main thread on Core1, with nothing on the Core1 virtual core to interfere.

 

8 texture loaders.

[DAL1850 51]

Not to put too fine a point on it, but 4094 would put the main FSX load on the virtual half of Core0 - an odd choice..

 

In that case, 4092 would make more sense ^_^

 

And we have a winner!

[Noel 4,573]

 

 

In that case, 4092 would make more sense

 

I'm afraid this one gets frame rate cycling slowing when nothing is changing in the sim, as in parked at the gate for example.   Maybe Bert's suggestion of 4084 makes the best sense, keeping the main thread off of two virtual cores.  Haven't confirmed but this one looks tempting for sure.

[cvearl 60]

"LOD_RADIUS=15 but it's NOT about distance"

 

Aaaaannnd... Wait for it.... Waaait foooor it....

 

That what she said! :He He:

 

AHEM! :Nerd: But seriously... I would love someone to prove that aiming at specific cores really helps in any way. I experimented and could never really tell if one setting helped over another.

 

C.

[cvearl 60]

Well, there are probably different reasons for HT being enabled, varying for different folks. Let's see:

 

1)  Ready-made PCs with HT type processors will come with HT already enabled. Many folks don't change it perhaps because they don't know how or simply don't want to mess with BIOS settings,

 

2)  Some folks do actually use their computers for things other than FS, and many other programs probably make better use of HT than FS, After all, I don't think Intel implemented it just to be a nuisance, it has uses.

 

3)  Having HT enabled doesn't make FS run any worse, and if the PC is not overclocked having HT enabled doesn't really make it run particularly hotter. Folks who want to extract the max clock rates out of their PC tend to disable HT to enable higher clocks without so much increase in temperatures.

 

There are probably other reasons. I don't really know why you are asking the question. I assume you've disabled it or don't have a processor with HT, so what is your reason?

 

Regards

Pete

 

Specifically #2 there are some games that run better with it but only slightly. But also apps that like it...

 

http://www.overclock.net/t/671977/hyperthreading-in-games

http://forums.anandtech.com/showthread.php?t=2274887

http://www.tomshardware.com/reviews/Intel-Core-i7-Nehalem,2057-12.html

[jabloomf1230 2,452]

I would love someone to prove that aiming at specific cores really helps in any way.

 

 

The reason that there are so many suggestions is that by setting an affinity for just FSX (or P3d), you are not doing anything about telling the OS how to assign other processes to the cores. Superimposed on that is the confusion over HT on or HT off (which shouldn't matter, except that it impacts the affinity mask numerology). Before this thread wandered away from its original focus, I posted a link to a previous thread about AM:

 

http://forum.avsim.n...mask-revisited/

 

You can also see what NickN's FSX Bible has to say about AM:

 

http://www.simforums.com/forums/the-fsx-computer-system-the-bible-by-nickn_topic46211.html

 

and

 

http://www.simforums.com/forums/the-fsx-computer-system-bible-in-pdf-format_topic46757_post284247.html#284247

 

A few choice quotes:

 

 

Standing on a barrel chanting Voodoo spells with a chicken and then trying or trading 'Affinity Mask' numbers along with tweak values with other users in forums will not make the sim run any better. All the user will accomplish is to eventually bring on another stutter, crash and the out of memory error. And every time you see a user post; "This tweak worked and my sim is perfect"  within 1-2-3 months that same user is right back in that forum looking for another fix or boost... it NEVER ENDSand the tweaks and settings they claimed were perfect in the past now seem to need another round of changes.!

Those who do this need to take their next paycheck and buy a clue.

 

Past that, the addition of Affinity Mask would only be used if its found to be 'required' and that is rarely needed unless the system is being tapped on core0 too hard, or, the CPU is of older design. Its a test and see process for that and there is a link that explains Affinity Mask from me included in the list under the Advanced use of Nv Inspector.

 

[Noel 4,573]

 

 

4084:    1111 1111 0100

 

Yer the Man Bert!  This one seems to work best, w/o the cycling issue.  Thanks!

[Bert Pieke 7,605]

Yer the Man Bert!  This one seems to work best, w/o the cycling issue.  Thanks!

 

I'm happy to hear that! 

 

On paper, at least, that is what would make sense, but the real world is often different..

 

B)

[Johan_Dees 84]

So, with a 4 cores, and 4 HT cores and wanting to free real core 0 what mask should I use ?

0111 0111 or 0111 1111 ? and what translates it into AM setting ?