It all depends on your system and setup, sliders, etc. IMO. You might find it works good for you with it on. I believe turning it off though takes better advantage of an oc and makes it generate less heat

Stupid question time: Why don't more games take advantage of HT? Is it because developers just aren't programming for it, or something else?

I'm not entirely sure but I think a lot of it just has to do with exactly the types of operations that HT is good for - real time game engines are notoriously hard to do parallel processing with because so many things that happen as they're running are inherently linear and serialized. In FSX it really only uses the the extra cores on a multicore CPU for some low level terrain title loading stuff in the background - the main thread that is the bulk of the simulation essentially has to be on just one core. There's a good document written a while back by Valve (makers of the Half-Life, Counter-Strike, Team Fortress and Left 4 Dead games) that explained why multithreading is so hard to do in video games... It's definitely not some magic thing where having 4 cores = 4X the performance as a single core. You have to have operations that can be processed in parallel without one relying on the others being finished first before it can start and stuff like that.

Ryan, i wonder then , the only diference between Quad Core OC at 3 like mine with a stock I7 with HT off is that the last one can be OC to 4?

No, the i7 is a completely different architecture (meaning how the chip actually processes data, the "pipeline" design) - even at the same clock speed as the Core 2 it'll be faster because of that.

Maybe you should turn it on because were all different and special in our own way. Maybe one day ompaloompas will prance around with hobbits under a double rainbow chanting songs of love.Until that day comes yeah leave it off!

Leave it off otherwise you'll be paying more in Carbon Tax.Pete Walsh.

sorry yet again for the double post:(

yup, i get more heat and I had a bsod; i need more voltage for HT; so for me it was not worth it for fsx. 2600k 4.7. 1.365

I'm going to ask a stupid question who's answer I could probably just find by doing a quick google search, but figure it would be easier to ask it here. (I do suffer from Laziness Syndrome): :( I do have HT On at the moment, by default - How do I turn it off?Also, for those of you who use http://www.venetubo.com/fsx.html to fix your FSX.Cfg, would turning HT Off make the recommended settings venetubo gave incorrect/obsolete?

I'm going to ask a stupid question who's answer I could probably just find by doing a quick google search, but figure it would be easier to ask it here. (I do suffer from Laziness Syndrome): :( I do have HT On at the moment, by default - How do I turn it off?Also, for those of you who use http://www.venetubo.com/fsx.html to fix your FSX.Cfg, would turning HT Off make the recommended settings venetubo gave incorrect/obsolete?

Open your BIOS and turn it off there.

well for FSX its useless to use it, but I have it enabled for folding on 4 phys cores and playing on other virtual ... performance is ok and do some good computing for "greater good" xD

well for FSX its useless to use it, but I have it enabled for folding on 4 phys cores and playing on other virtual ... performance is ok and do some good computing for "greater good" xD

If HT is enabled than all 8 cores are virtual.

If HT is enabled than all 8 cores are virtual.

yy they are, but I ment it some other way ... folding on all 8 HT cores are not much better than folding on 4 cores, but power available from other 4 non-folding cores are sufficient for FSX ;)

I'm not entirely sure but I think a lot of it just has to do with exactly the types of operations that HT is good for - real time game engines are notoriously hard to do parallel processing with because so many things that happen as they're running are inherently linear and serialized. In FSX it really only uses the the extra cores on a multicore CPU for some low level terrain title loading stuff in the background - the main thread that is the bulk of the simulation essentially has to be on just one core. There's a good document written a while back by Valve (makers of the Half-Life, Counter-Strike, Team Fortress and Left 4 Dead games) that explained why multithreading is so hard to do in video games... It's definitely not some magic thing where having 4 cores = 4X the performance as a single core. You have to have operations that can be processed in parallel without one relying on the others being finished first before it can start and stuff like that.

I figured it had something to do with it being difficult to process things on multiple cores, but wasn't sure. Thanks for the reply.

biggest problem is to synchronize computing of real time simulation (when it depends on another stuff in simulation). Everything is depending on another things while in converting video (or other stuff) your only concern is which part you want to process by which core. This is not the only one problem, but most understandable one ;)

Hyper-threading attempts to enable more idle CPU cycles to be utilized for something useful. There are many times the CPU is idle waiting for something. During these idle periods HT tries to make the processor busy more often by processing threads that would otherwise be waiting. The CPU is in effect trying to predict the future, and often gets it wrong, hence why FSX stutters more with it ON than OFF. IT also affects the system overall.As for apps not being design to handle HT - that is rubbish. You can split your app into multiple threads but anyone who does any serious multi-threading will know, there mere act of multi-threading an app can result in a slower execution time than if it was left as a single thread due to threads using shared data ending up waiting for each other to finish executing. HT simply tries to exploit the way threads work, it does not require special programming actions on the part of the programmer.The apps most easiest to multi-thread are those that operate on their own data and do not cross-communicate or share data, so do not end up waiting for each other.Best regards,Robin.

Ok guys!I finally ended my OC setup!I´m currently running @ 4GHz with HT OFF and Temps around 69C and 71C at full load on IntelBurn Test.The most incredible part was see the amount of performance gain by FSX! :( I got something around 11FPS at JFK with full traffic load and lot´s of weather and now I´m seeing 20 FPS which is locked by FPS Limiter.From PCMark05 prospective the performance gain was 40.8%!So I would like to thank you all for the quick answer and help everybody gave me.