Hyperthreading - Yes it DOES help!

[ArjenVdv 190]

Hello,In the i7 or i5 thread there were people saying that you better buy an i5 2500K over an i7 2600K, because it's not worth paying so much extra for a CPU with hyperthreading, that FSX could not use anyway. I have an i7 860 2.8 (OC 4GHz) myself, so I thought, let's test this! And the outcome was surprising. First of all these are my overclock settings:Base clock: 200Multiplier: 20xC1E = offEIST = offTurbo boost = offMemory ratio = 4xQPI ratio = 16xVCore = 1.4VCPU VIT = 1.3VVMemory = 1.65VSpread spectrum = offHyperthreading = ONThe test was using the NGX, at Aerosoft Amsterdam (extremely frame rate heavy), runway 36R, fair weather, time 7:29 am. I used REX and ENB Series. Also I used Bojote's tweaked fsx.cfg Results: 18 - 22 fps. Now the next test:Base clock: 200Multiplier: 20xC1E = offEIST = offTurbo boost = offMemory ratio = 4xQPI ratio = 16xVCore = 1.4VCPU VIT = 1.3VVMemory = 1.65VSpread spectrum = offHyperthreading = OFFAs you can see, HT has been disabled now. I loaded the exact same circumstances again, time maybe only a few minutes later, and these were the results:14-16 fps!This is quite a big difference. Both circumstances were exactly the same, I restart my pc for both test and didn't load any other programs apart from FSX.So I don't know why people are saying that HT doesn't, because there is a noticable difference. Maybe FSX does not support HT, but your OS does, maybe HT helps to run your OS better, so there more room left for FSX. Comments are very welcome!

[Kosta 122]

I pretty much know why you had that difference:You ran the PC through the bojote's cfg, which set the affinity mask according to the tool (core 1,2,3), with HT on. Then you turned HT off, which basically rendered affinity mask bogus (meaning FSX was set to use false cores, in the end using less cores on non-HT setup).Affinity Mask must be re-set. HT brings nothing. It has been confirmed many times.

[dazz 69]

I pretty much know why you had that difference:You ran the PC through the bojote's cfg, which set the affinity mask according to the tool (core 1,2,3), with HT on. Then you turned HT off, which basically rendered affinity mask bogus (meaning FSX was set to use false cores, in the end using less cores on non-HT setup).Affinity Mask must be re-set. HT brings nothing. It has been confirmed many times.

Listen to Mr Word Not Allowed here guys. He knows his stuffThere's a very easy way to test HT and see how it's completely useless in FSX, even when you could potentially use some extra cores:Disable two or three cores and test 2C/4T vs 2C/2T or 1C/2T vs 1C/1T

[Kosta 122]

Listen to Mr Word Not Allowed here guys. He knows his stuffThere's a very easy way to test HT and see how it's completely useless in FSX, even when you could potentially use some extra cores:Disable two or three cores and test 2C/4T vs 2C/2T or 1C/2T vs 1C/1T

Thanks Dario.Moreover, one can notice in task manager that there is something being measured there (but it's false), but in the end, FPS won't budge a single digit.

[ArjenVdv 190]

Affinity mask has been set to 14.I don't entirely know what you mean with "bogus" mr. Word Not Allowed, could you explain please?Btw, what's the best affinitymask setting for HT off?And also, why do you have an i7 2600k when you say HT is useless?

[Kosta 122]

Affinity mask has been set to 14.I don't entirely know what you mean with "bogus" mr. Word Not Allowed, could you explain please?Btw, what's the best affinitymask setting for HT off?

And it was set for both HT-on and HT-off test to 14?

[ArjenVdv 190]

And it was set for both HT-on and HT-off test to 14?

I didn't change anything to the FSX.cfg at all.

[Kosta 122]

I didn't change anything to the FSX.cfg at all.

That's exactly the wrong thing.Do you even know what affinty mask in fsx.cfg is doing?

[ArjenVdv 190]

That's exactly the wrong thing.Do you even know what affinty mask in fsx.cfg is doing?

Correct me if I'm wrong, but as far as I know, affinity mask tells FSX which cores do use? In this case core 1 and 4. Are there more optimal settings for affinitymask? Like 123?

[MrKen 3]

Correct me if I'm wrong, but as far as I know, affinity mask tells FSX which cores do use? In this case core 1 and 4. Are there more optimal settings for affinitymask? Like 123?

So with an affinity mask of 14, fsx isn't allowed any of the virtual cores. They have absolutely no work from fsx.To actually do a test properly you'll need to set the proper affinity mask for each codiguration, run each scenario multiple times for more than just a few seconds, run the above in multiple traffic/weather/scenery setups. To be a legitimate, definitive test you'd have to make a few hundred such runs and have a concrete performance measuring method to compare not just framerates, but also smoothness at that framerate.

[Kosta 122]

Correct me if I'm wrong, but as far as I know, affinity mask tells FSX which cores do use? In this case core 1 and 4. Are there more optimal settings for affinitymask? Like 123?

Oh well, I'm out again educating others Affinity Mask setting is a binary code, yes, for telling FSX which cores to use. But it's not being set by numbers, but rather binary code.So binary for 14 is 1110. And you gotta look at it reversed... meaning cores 123 are going to be used. The 0 is core 0. Which is being left out.So if you take your typical HT-on situation and you apply the Affinity Mask 14, you have 0000 1110, equivalent to telling FSX to use HT-core of the Core0, Core1 + HT. Get it?Why your FPS was higher in HT-on, beats me now, but I can tell you for sure that FSX took longer to load, since you cut off the texturing threads by giving FSX AM=14 in HT-on configuration.Hope that helps.

So with an affinity mask of 14, fsx isn't allowed any of the virtual cores. They have absolutely no work from fsx.

Err no, 14 DOES allow virtual cores in HT-on configuration. Correct AM in HT-on config would be either:84 - FSX uses Cores 1 2 and 3, NO HT cores used252 - FSX uses Cores 1 2 and 3, HT cores used Both of these can be used when HT is on.For HT off, 14.

[MrKen 3]

Err no, 14 DOES allow virtual cores in HT-on configuration. Correct AM in HT-on config would be either:84 - FSX uses Cores 1 2 and 3, NO HT cores used252 - FSX uses Cores 1 2 and 3, HT cores used Both of these can be used when HT is on.For HT off, 14.

You're right. I realized that after posting

[ArjenVdv 190]

Oh well, I'm out again educating others Affinity Mask setting is a binary code, yes, for telling FSX which cores to use. But it's not being set by numbers, but rather binary code.So binary for 14 is 1110. And you gotta look at it reversed... meaning cores 123 are going to be used. The 0 is core 0. Which is being left out.So if you take your typical HT-on situation and you apply the Affinity Mask 14, you have 0000 1110, equivalent to telling FSX to use HT-core of the Core0, Core1 + HT. Get it?Why your FPS was higher in HT-on, beats me now, but I can tell you for sure that FSX took longer to load, since you cut off the texturing threads by giving FSX AM=14 in HT-on configuration.Hope that helps. Err no, 14 DOES allow virtual cores in HT-on configuration. Correct AM in HT-on config would be either:84 - FSX uses Cores 1 2 and 3, NO HT cores used252 - FSX uses Cores 1 2 and 3, HT cores used Both of these can be used when HT is on.For HT off, 14.

I got it pretty much entirely now, but: you say with HT on I should use AM=252, and with HT off AM=14 right? But I'll get exactly the same performance in both circumstances? Let me try that. Also you said that with HT off FSX is loading faster right? Because of texture threading or something you said right? (Can't find that post anymore because you edited it).

[Kosta 122]

I got it pretty much entirely now, but: you say with HT on I should use AM=252, and with HT off AM=14 right? But I'll get exactly the same performance in both circumstances? Let me try that. Also you said that with HT off FSX is loading faster right? Because of texture threading or something you said right? (Can't find that post anymore because you edited it).

FSX has 3 parts (according to Bojote) which are being put on separate cores.Fibers = not movable, Core0 always.Main Thread= movable, but always on the "first" one, so that is why Core1,2,3 config, so that main thread is separate from Fibers.Rest are texture loaders.Texture threads (loaders) have nothing to do with HT on or off.Test:HT-on, AM=252HT-off, AM=14 Good luck and good night!

Also you said that with HT off FSX is loading faster right?

And no to this one. It has everything to do with texture loaders. More texture loaders, faster disk, FSX is loading faster.

[MrKen 3]

Just checking my math, would it be 252 or 254 for all on except physical core 0? I thought 255 would enable them all, 0-7.