Hyper-Threading problem [SOLVED (sort of)]

[Martox29a]

Hello everyone and sorry for my bad english, i'm a little out of practice with it.

I'm running X3 TC on my system: Windows Vista Ultimate 32bit sp2, Intel i7 920 @ 2,67, Nvidia GeForce GTX285 and 3 GB of dd3 tri-channel RAM; and experiencing some major drops in FPS during SETA (with interface flickering and disappearing), nothing game breaking but still disturbing. I read a lot about similar problems on this board but never found a definitive solution to them. Tonight after some experimenting i finnally sorted the problem out, so i wish to share this knowladge with the community.

The problem on my system was not related to any common issue discussed on this board, such as invasive audio/video codecs, old drivers or un-optimized systems. The FPS drops were not related neither to the GPU power (not eaven nearly stressed by the game, no matter the settings), nor to the system RAM (never fully used) or the Page File (optimized). What caused the slowdowns on my system was apparently the CPU!! I noticed that during SETA the cpu usage increased, but never exceeded 15% wich is the load of a single Thread. The game was not using a single CORE (as it is supposed to do, since TC is a single-core application) but a single THREAD: 1/2 CORE!!!
So i disabled Hyper-Threading (through BIOS) and now the game runs fine! The cpu usage increased to 29% and while i'm still getting some fps drops in SETA they are hardly noticeable without FRAPS. With this little trick i got a huge boost in performace and so i decided to share this with you, hoping to be of help.


I can't really say if there is something wrong about how the game handles intel Hyper-Threading (at least on i7s) or if there is something wrong about how my system handles it (everything seems in order though...). All i can say is that after months of reading this forum i'm pretty sure i'm not the only one having this problem. Disableing Hyper-Threading is a viable solution in my opinion (sort of ): having 8 cores is not a crucial need for everyday computing, and it can be reactivated at will without much efforts...

Oh and... almost forgot: thanks to Egosoft for this great game!
Bye

[CBJ]

I'm not sure where you've got the idea that the game could somehow use two threads if they are on the same core. A single-threaded application is a single-threaded application, and whether the threads are on one core or several is neither here nor there.

Your change in CPU usage figures when you disable HT is also a misunderstanding on your part. If you disable HT then you're changing the number of available threads from 8 down to 4, so of course the usage is going to appear to double. The game is using one of 8 available threads (max 12.5%) with HT on, and one of 4 available threads (max 25%) with HT off. The extra few percentage points over the above figures are the rest of your system and things like drivers used by the game that are able to operate on a different core. Disabling HT will have had little or no effect on the real performance of your game I'm afraid.

If you are having performance problems with the game then I suggest you post the information requested in the very first thread in this forum, and provide a little more information about the nature of the problem and the circumstances in which it occurs.

[Martox29a]

I'm not sure where you've got the idea that the game could somehow use two threads if they are on the same core. A single-threaded application is a single-threaded application, and whether the threads are on one core or several is neither here nor there.

I didn't say that, i said that with HT active the game was using only 1/2 of the core power, i deduce it by mesuring cpu usage% and cores temperatures. This may be wrong, but disabling HT solved all my problems and this must mean something.

Disabling HT will have had little or no effect on the real performance of your game I'm afraid.

This is definitely not the case: i'm experiencing a huge performace boost after disabling HT. I can't say if it is a problem of my system or a problem of the game, but i'm talking about a +20-30 FPS boost during SETA, not something that goes unnoticed. As soon as i re-enable HT i experience fps drops again: one can hardly be wrong about that.

If you are having performance problems with the game then I suggest you post the information requested in the very first thread in this forum, and provide a little more information about the nature of the problem and the circumstances in which it occurs.

I wasn't asking for help really, i was offering it. I'm not having performance problems anymore.

[CBJ]

I didn't say that, i said that with HT active the game was using only 1/2 of the core power, i deduce it by mesuring cpu usage% and cores temperatures. This may be wrong, but disabling HT solved all my problems and this must mean something.

The game will only use one thread. If you halve the number of available core threads then it is a simple mathematical fact that the percentage utilisation will double. Whatever it means, it isn't what you initially thought it meant.

This is definitely not the case: i'm experiencing a huge performace boost after disabling HT. I can't say if it is a problem of my system or a problem of the game, but i'm talking about a +20-30 FPS boost during SETA, not something that goes unnoticed. As soon as i re-enable HT i experience fps drops again: one can hardly be wrong about that.

If what you describe were indeed the case then some of the many thousands of other players running a PC with an HT-enabled processor (myself included) would surely have noticed by now. More likely, the changes you see are coincidental, or caused by something else on your system being affected by HT being disabled.

I wasn't asking for help really, i was offering it. I'm not having performance problems anymore.

Disabling HT isn't really a great solution, either for you or for anyone else. I was suggesting that you posted the information so that we could try to find a better solution for you.

[AstralWraith]

I just tried this on two of my computers at my house and both showed an increase of about 40-60% on SETA depending what is going on. The big issue I was having is turrets stopped firing when SETA was active and I'm running an overclocked core i7 with 3-channel memory. Now they actually fire so I believe there is indeed some merit to this.
I don't mean to argue CBJ but maybe it is a particular implementation of Hyper-Threading on our generation of CPU that x3 perhaps just doesn't like much or something.

EDIT: Sorry for necro, I just feel it is important but doesn't warrant a thread being created again when this is the top search result on google that I found. I tried disabling HT on a dual core core2duo I have, I got about 5-10% increase, I think it might be related to the fact that HT does use some CPU time moving threads around when HT is enabled, and sometimes in odd circumstances the 'hiccup' caused by the thread switching can actually cause a twofold issue as the application tries to recover after said hiccup.

[Cycrow]

as ur running an overclocked cpu, its possible that with HT on your overclock is actually unstable, enough to cause performance problems.

most people who overclock usually disable HT to increase stability.