Sign in to follow this  
mgh

Dual core and 64bit with FSX...

Recommended Posts

Do you know if FSX will support dual core processors and/or 64bit feature?THX for resposes! :-)AQUI

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

I'm glad somone asked...I was about to post the same question: Will FSX support dual cores from AMD?David

Share this post


Link to post
Share on other sites

I suspect the question is not "support" (which is really more of an operating system issue) but rather "opotimized for". It appears that many important tasks in FS are run as fibers within a single thread. That suggests to me it might be difficult to do a load-sharing on multiplke cores, because of scheduler issues.scott s..

Share this post


Link to post
Share on other sites

>I suspect the question is not "support" (which is really more>of an operating system issue) but rather "opotimized for". It>appears that many important tasks in FS are run as fibers>within a single thread. That suggests to me it might be>difficult to do a load-sharing on multiplke cores, because of>scheduler issues.>>scott s.Scott is correct. As with SLI there's nothing the app has to do to "support" dual-core CPUs other than have more that one thread. The OS scheduler does the rest. FS2004, in fact, was multi-threaded. But as Scott also correctly points out it's up to the app to use multiple threads effectively.In something like FS, which consists of numerous interdependent systems, eventually some threads have to be suspended until the threads they are waiting on are ready. The programmer has to think careful about these interdependencies when they are designing the system. In the worst case there can be so much waiting that the end result looks more like a single threaded app.It gets real tricky. Still, here's what Task Manager showed recently on my Dell 370 with an Intel dual core chip:

Share this post


Link to post
Share on other sites

Interesting Mike. I hadn't thought to test it out in TM, here is what I got with an X2 4800 (FSD Porter VC at TNCM real weather), wonder If I am missing having something enabled after looking at yours (time to go poke around in the Bios).Although I was excited to "finally" have all sliders maxed and ony 58% CPU usage for once, LOL.Regards, MichaelKDFWhttp://www.calvirair.com/mcpics/mcdcvabanner.jpgCalVirAir Internationalhttp://forums.avsim.net/user_files/139995.jpg

Share this post


Link to post
Share on other sites

I read an interview with John Carmack a while ago where he said he was hoping that the compilers will do the job of optimising multi-threading one day. Wouldn't that be nice? Multi-threaded programming is the HORROR and I symphasise deeply with anyone who has to do it...Christian

Share this post


Link to post
Share on other sites

The real trick with multi-threading is making sure your threads access shared memory properly.The apps that I write professionally are multi-threaded. The threads are event driven and react to drivers that are interfacing with specialized telecom boards. I use threads in order to take advantage of multi-cpu computers. Each thread has to access shared memory structures and objects (I write in that ancient language - c++) and if you do not manage with sempaphores and critical sections, you will definitely get bugs and crashes which can require a significant amount of time to debug.You also have to make sure your threads yield back to the CPU for other processes (and their threads).You also need to take care that you don't have threads getting into race conditions or deadlocking. Further, you don't want threads waiting too long for access to shared objects, since they will not be able to process events, in my case these events can be generated by the bucket load every millisecond.That being said, it is a challenging method to accomplish tasks, and quite rewarding too.

Share this post


Link to post
Share on other sites

Oh ok. Optimization is the key, then. It does sound complex to do in FS. Thanks Scott and tdragger for the clarification.:) David

Share this post


Link to post
Share on other sites

>I read an interview with John Carmack a while ago where he>said he was hoping that the compilers will do the job of>optimising multi-threading one day. Wouldn't that be nice? >>Multi-threaded programming is the HORROR and I symphasise>deeply with anyone who has to do it...>>Christian>Another mythical silver bullet. The compiler is not going to re-write your application. For instance, how will it know that it's okay to move texture load tasks to a background thread but that frame buffer setup needs to be on the foreground thread? Nope, developers are still gonna have to understand how it works.

Share this post


Link to post
Share on other sites

Yeah, I am not sure how compilers could help. I use compilers every day and these are fairly dumb programs that parse your source and create an executable. Compiler is not going to fix your bugs or optimize your code if it is already poorly written. Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

Share this post


Link to post
Share on other sites

>It gets real tricky. Still, here's what Task Manager showed>recently on my Dell 370 with an Intel dual core chip:>The image shows that the FS9 process is bounced between the two cores with almost 58% total CPU usage. If you assign the FS9 process only to one core, the performances will be better because the bouncing process speed down overall performances. This is why you obtain 58% CPU usage instead of 50% usage of CPU. The remaining 8% CPU usage is for the bouncing process. Actually the best configuration to use FS2004 with dual core CPUs is to assign FS9 process to the first core and all other processes (antivirus, third party programs, etc) to the second core. I hope that FSX will optimize the processes to obtain a 100% dual core CPU usage without bouncing processes.Best RegardsAQUI

Share this post


Link to post
Share on other sites

Clearly FSX is optimized for multiple CPUs and multithreaded. We all know that You're (Jason) using XP and not Vista- at last for now. Just wait until you get that DX10 Hardware....Just beacuse an app is multithreaded, does not meant that multiple CPU's have any effect on performance :)So here's what we can draw for conculsions so far-Multithreading that supports multiple cores (not Hyperthreading!) Does that mean that a dual multicore has further benefits? Granted, I beleive that one needs a server OS at that point- 4 cpu's :)DX10 support somewhere near launch, DX9 OOB. Might be shipping on the DVD, might be an update. Depends on factors out of the dev teams control (hardware to test on, etc.) I'll bet that there is an awful lot that you can do with the new shaders in FS. See the crysis (crytek) demo/movie here: http://www.gametrailers.com/Methinks that there is software emulation for the DX10 shaders running somehwere in the Game Studios labs...Get lots of video memory- 256 is OK. How about 128?No 'specific' support for SLi, but that's a driver function as opposed to a design decision.Hopefully there will be the ability to have hyper detailed mesh- imagine drainage ditches :) roads that can actually pass under taxiways and the like.Tim

Share this post


Link to post
Share on other sites

Well, that's a bit unfair I think. The VC 2003 compiler can recognise some neat stuff like not obvious constant expressions or move a calculation out of a loop if it shouldn't be in a loop (ie the iterator isn't part of that calculation), so they aren't completly dumb. As for the future, I wouldn't be surprised if compilers get a whole lot smarter - it makes sense too, why not let the computer do the work, that's what they're there for in the first place. Not an excuse for writing bad code, but it would be handy if some aspects of coding would be made easier...Anyway, I'm not going to argue here about what compilers will be able to do in the future. I have no idea what's involved in writing a compiler, I just know them well enough so I can get on with my day job...Christian

Share this post


Link to post
Share on other sites

But our simulator isn't a game! Flight Simulator needs CPU power and then GPU power! Aqui :-)

Share this post


Link to post
Share on other sites

I can across the following Microsoft article from MSDN Magazine (October 2005) on using OpenMP to achieve multi-processing.http://msdn.microsoft.com/msdnmag/issues/05/10/OpenMP/Figure 9 shows serial vs parallelised performance on 2 processors. The example chosen is a simple loop. The figure shows that with more than 100,000 iterations parallel processing is about 1.7 times faster than serial processing. However, there's no speed advantage unless then number of iterations is more than 5,000, and at less than 100 iteration the speed of parallel processing is about a tenth of serial processing. The reduction is because of the overhead associated with parallel operation. I don't know how relevant this would be to Flight Simulator but, at the least, it suggests that improvements in speed may not be as great as might be expected.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this