Hi,There have been quite a few posts on various forums about people with dual core CPUs but only one core being used by the FSX demo. I have a P4 3GHz with HT (i.e. two virtual cores) but the same will probably apply to real dual core CPUs (Athlon X2, Intel Core Duo, etc.).When I launch FSX it initially only runs on one of the 2 virtual cores as shown below:http://forums.avsim.net/user_files/153874.gifThen I go to the "Processes" tab of task manager, right click on the fsx.exe process and choose "Set Affinity..." from the drop down menu. In the popup I uncheck CPU1 as shown below:http://forums.avsim.net/user_files/153875.gifThen OK that window, go back to FSX for a few seconds and you will see it is all running on one CPU.Now here's the trick: Go back to the fsx.exe process affinity screen and put back both CPUs as shown below and OK the window:http://forums.avsim.net/user_files/153876.gifNow go back to FSX and unpause it and then look at the performance tab of the task manager:HEY PRESTO!!!Windows or FSX (I don't know which one) is now load sharing across both logical CPUs as show below:http://forums.avsim.net/user_files/153877.gifI can't try this on an athlon X2 or core duo but maybe some of you who have been experiancing issues can...Kind regards,JCMK

Now the interesting question is: does it speed up the sim? If so, how much?Regards,http://www.bremmekamp.com/img/misc/avsim.jpg

I tried it on my X2, but it doesn't seem to make any difference.

Hardly surprising. If the program code doesn't parallelize tasks effectively, having the game run on 100% of one core or 50/50 of both can hardly make a difference at all.Not saying that it's MS fault if there is not much parallelization taking place under the hood of FSX. Most people seem to forget that the most useful parallelization in game programming is now at least ten years old - having a dedicated GPU handle the graphics stuff. No matter how many CPU cores there are, it's hard to find them something to do concurrently.Regards,http://www.bremmekamp.com/img/misc/avsim.jpg

I spent about 1 hour testing it, I have dual core AMD. Result: No Difference :-fume

Indeed.. the code needs to be programmed to make use of multi-threading, so that each processor can have it's own processes assigned. Actually i think i read somewhere that they're working on that.. i'm just a little concerned to see no sign of it in the demo yet. Maybe one of the ACES guys can comment on this?

Everyone is very concerned about the multicore performance but i think we have to acknowledge that the multicore architecture is not the massive performance enhancer we are sometimes led to beleive.It is not always possible to break up code equally to spread across multiple processors. Some processes have to run in sequential order so even if one were to split them between cores you'd find that one couldn't run before the other had completed..From some of the results I've seen people are getting usage on both cores so it looks like some processes have been split, it may be that there is nothing more that can be done.The simple truth is although a two core processor theoreticaly has available twice as much computational power to its single core equivalent, that power is extremely difficult to extract - especially when you are talking about something like a video game which has a large percentage of its processor usage in one render loop.

If considering that for a game with a "render" loop, a second processor would not help much (there has been a very nice presentation of John Carmack - developper of DOOM and QUAKE engines at Quake4Con lately about this), I think that it is GREAT that the second CPU is not much used by FS: it may at last be the time for third party vendor add-ons to exploit the "free" second core for even more deep and feature rich add-ons. Isn't this a great open door?

Lets hope so! :)

>If considering that for a game with a "render" loop, a second>processor would not help much (there has been a very nice>presentation of John Carmack - developper of DOOM and QUAKE>engines at Quake4Con lately about this), I think that it isA one hour ramble is hardly a presentation, but it was a worthwhile keynote speech nonetheless. ;)>GREAT that the second CPU is not much used by FS: it may at>last be the time for third party vendor add-ons to exploit the>"free" second core for even more deep and feature rich>add-ons. Isn't this a great open door?Maybe for some, but most addons run within the process of FS9/X, so I wouldn't think those addons can utilize the free core at all. Of course you can e.g. set up your ActiveSky to use the other core, but that's neither new nor does it much for FS performance.Regards,http://www.bremmekamp.com/img/misc/avsim.jpg

nem,Yeah, but your just talking about one app. What if you have say ASV6, FSPassengers, FSInn or Squawkbox, FS Flight Keeper, FSHotSeat, and Teamspeak all running at once?(if those can all work together). If you don't have a second PC to use WideFS, but do have a latest and greatest Core 2 or AM2 system I would think you could put that second core to use here.Jean-Luc,>If considering that for a game with a "render" loop, a second>processor would not help much (there has been a very nice>presentation of John Carmack - developper of DOOM and QUAKE>engines at Quake4Con lately about this), I think that it is>GREAT that the second CPU is not much used by FS: it may at>last be the time for third party vendor add-ons to exploit the>"free" second core for even more deep and feature rich>add-ons. Isn't this a great open door?>Yes, please have a look at my reply in this thread here, I kind of made it with you in mind ;) ...http://forums.avsim.net/dcboard.php?az=sho...&topic_id=12437Cheers,OneTinSoldier

>Yeah, but your just talking about one app. What if you have>say ASV6, FSPassengers, FSInn or Squawkbox, FS Flight Keeper,>FSHotSeat, and Teamspeak all running at once?(if those can all>work together). If you don't have a second PC to use WideFS,>but do have a latest and greatest Core 2 or AM2 system I would>think you could put that second core to use here.At least FSP is an FS module (to shorten the list a bit ;)).And of course, if you don't have another PC to have this stuff running on, a second core comes in handy. Providing there is enough RAM of course, which would be a much more important point - the apps you listed use next to no CPU resources, compared to FS, but if you only have 1-1.5 GB RAM you will still want to run at least some of them on a second PC instead of a second core.Regards,http://www.bremmekamp.com/img/misc/avsim.jpg