Ht turned on=magic

[Anthony25368 5]

I have been using fsx with hyper threading on my i7 turned off with dx9. I changed to dx10 and didn't change it but had lots of stutters bad frames and all the problems that people have been reporting. I do not over lock but I have affinity mask set at 255. Maybe worth a try if you are having performance problems.

[Jim Young 2,356]

Strange as NickN says "FSX makes NO USE of hyperthreading".  Believe Paul J does not recommend it either in his guide.  It supposedly makes it easier to overclock with lower temps and better stability too and it will in no way improve Flight Sim performance - http://www.simforums.com/forums/the-fsx-computer-system-the-bible-by-nickn_topic46211.html.  Sometimes things like performance looks good when you first change a setting (like hyperthreading) or add a tweak.  A placebo.  Hopefully no one here will follow your guidance.

 

Best regards,

[SirStiggie 63]

Finally, someone else see's what I've been seeing. For whatever reason, my system runs significantly better with HT on than off. It is more stable and a lot smoother.

[Anthony25368 5]

All I wanted to do was tell people to try it if they are having stutters. I do see a big difference in performance and I have tried all sorts of combos with ht off. Just a little heads up.

[fppilot 4,339]

Strange as NickN says "FSX makes NO USE of hyperthreading".

 

I am curious about other things running at the same time as FSX.  I have a Gateway gaming system and the BIOS does not give me any control over HT.  It is on whether I like it or not. I am using all 8 cores.  I understand FSX does not utilize HT.  But how about REX, AS, Spad, you name it.  Since I am connecting to the web when using FSX I leave my AV running.  i have other things running such as Intel Rapid Storage Technology and Epson Event Manager.  Question is if FSX does not use HT, does any of this other stuff?  And if so does that then make a difference when using FSX?

 

My FSX runs smooth with no stutters.  Never had them.

[Paul J 349]

Jim is correct, inasmuch as for years I followed the overclocking mantras 1). "always overclock with HT off": and 2). "FSX only uses Core #1..."..... but... following a number of test sessions a couple of months ago, I found that - and became quite convinced - that HT on narrows the average frame fluctuation percentage by several points: i.e. HT Off gave a FR Av. of 6%, whereas with HT on it dropped to between 3 and 4%. It made the sim feel smoother. We must be careful not to be sheep, sometimes! :lol:

This is fairly significant in areas where frame rates fluctuate widely. I noticed no change in the heat of each core, nor did the system become unstable. As a result I re-vamped the "How-To" guide to reflect this shortly after the tests.

 

By answer to FP - yes - Windows 7-8 and the i7 architecture, and programming techniquies used nowadays - most definitely the other apps/addons will make use of whatever processing power becomes available.

 

Regards,

 

pj

[Jim Young 2,356]

 

 

Question is if FSX does not use HT, does any of this other stuff?

 

No, because FSX is the engine that runs the addons.  Now for other games you might own, they may use HT, but not FSX.  P3D might the ability but it's still being tested and studied to see if there is any effect.

 

Best regards,

[fppilot 4,339]

Jim,

My REX is running before I have it launch FSX.  I also start Spad before I start FSX.  FSX has nothing to do with my AV or with my Epson Status Monitor, or Intel Rapid Storage...........

 

I don't use other games.  Just FSX.

[gboz 157]

No, because FSX is the engine that runs the addons.  Now for other games you might own, they may use HT, but not FSX.  P3D might the ability but it's still being tested and studied to see if there is any effect.

 

Best regards,

 

 

Am I missing something here.

 

This is Task Manger showing my Haswell with HT on running FSX only, AffinityMask=252.

 

Certainly looks like cores 2,3,4,5,6,7 are working well.

 

gb.

[Michael Moe 493]

Am I missing something here.

 

This is Task Manger showing my Haswell with HT on running FSX only, AffinityMask=252.

 

Certainly looks like cores 2,3,4,5,6,7 are working well.

 

gb.

 

 

I will try it out later to night (local in 8 hours) and see what freq i can overclock with HT=ON

 

Will report back

 

Michael

[Anthony25368 5]

I have been using fsx with ht on for a week now and there is a difference for sure on my computer. I have and i7 but I don't overclock. I would guess if you do overclock there might be problems with temp, but it might be worth a try. I use affinity mask of 255.

[gboz 157]

I will try it out later to night (local in 8 hours) and see what freq i can overclock with HT=ON

 

Will report back

 

Michael

 

 

I have been using fsx with ht on for a week now and there is a difference for sure on my computer. I have and i7 but I don't overclock. I would guess if you do overclock there might be problems with temp, but it might be worth a try. I use affinity mask of 255.

 

 

There is no problem overclocking with HT on as long as you realise that:

 

1: You will not get as high an OC for a given CPU temp.

2: For a "HT on" OC you should go back to default non-overclocked settings

   and start the overclocking process from scratch.

 

gb.

[Jim Young 2,356]

All I can do is provide info from the "experts" ....

 

http://forum.avsim.net/topic/341157-is-hyperthreading-a-good-thing-for-fsx-performance/

http://www.overclock.net/t/846522/flight-simulator-x-support-intel-i7-hyper-threading

http://forum.avsim.net/topic/241915-hyperthread-fsx-i7-and-you/

 

Respectfully, this topic has been discussed to death.  It's best one conduct a search of the forums (and the Internet).  Unfortunately, they will see the same things being discussed over and over and over.  If HT works for you, great!  We do not recommend it though.

 

Best regards,

[Kattz 132]

My system is OC'd 1.4 gig over the stock 3770K clock.  I have never turned off HT, but I'm not using the Affinity Mask = XXX setting in my FS.cfg either.  Runs great.

[TheFamilyMan 279]

Phil Taylor in his FSX blog stated that FSX will run perfectly well on HT enabled multi-core systems without the use of any fsx.cnfg affinity tweaks.  I don't use HT because at least in my case (and as mentioned above) I can hold a stable 4.5 OC at meaningfully lower voltages and thus have lower temps (which I've tested and confirmed with FSX), both which equate to less stress on my 4770k.  And as is well known, FSX also runs perfectly well without HT enabled. BTW, if I didn't OC my system I'd leave HT enabled.

 

sorry...yet one more kick in that horse...