Official forums for BZFlag.org

Ok, I've seen several players now whose tanks are behaving unnaturally due to "dual core", and I'm curious... would dual core actually change the gameplay? The strange movement includes excessive jitter, randomly increasing tank speed and/or shot speed (not sure on shots, but I am really sure on tank speed) and causes them to jump higher or shorter with large amounts of jitter and different speeds as they do so. (as in, fall faster, climb faster, etc.)

And what could be done for them to fix this?

You mean a dual-core processor? I've been playing on one for about 1 1/2 years now, haven't noticed a thing. AMD 4400+ CPU and Kubuntu Linux OS. I really don't see how that would change things at all. It's just a second processor stacked on top. Maybe we're talking about something else.

I don't know anything else by that name computer related except the processor, so you're probably right.

They could have been running BZFlag in threaded mode, which I have been told is very buggy?

Some people experience issues with gameplay on dual-core systems. It has to do with the single thread possibly hopping between cores with buggy BIOS or driver versions. One thing they can try to see if this is the issue, is to set the bzflag.exe process to a specific core using the Affinity setting in the Task Manager.
Have them start BZFlag, and minimize it. Then, from the Processes tab in Task Manager, do the following:

1. Locate bzflag.exe and right click on it
2. Select "Set Affinity..."
3. Uncheck all but a single core
4. Click OK, and return to the game

If that fixes the problem with studdering, it's an issue with "clock skew".
NOTE: The affinity setting will not be saved for next time. It would have to be done every time the game is started, unless they can find an affinity utility.

Here is some information about this issue:
Game Timing and Multicore Processors

As well, they might need to download new drivers for their processor (in this case, I'll give the example of the AMD X2):
AMD Athlon 64 X2 Utilities and Updates (AMD Athlon™ 64 X2 Dual Core Processor Driver for Windows XP and Windows Server 2003)

I found these two links from another forum.

I've run bz on dual cores - and multi processors. No problems here.

I've heard that it is generally a Windows problem... mostly with C2D chips, though I could be wrong. I can't really vouch for it because I almost never use Windows on my C2D lappy and don't even have BZFlag installed... I think.

I've heard of it more with AMD chips. I myself have never encountered it. I'm assuming it could happen with both Intel and AMD dual-core systems, for likely the same exact reasons. In either case, checking for Windows Updates, processor driver updates, and BIOS updates is a good thing to check.

On windows, BZFlag uses QueryPerformanceCounter to obtain delta time, and on Linux/Unix it uses gettimeofday. I only went back to version 2.0.4 to check. Looks like BZFlag is already doing what it can to provide accurate timing. If this is a constant problem maybe you should look into a BIOS upgrade.

According to microsoft QueryPerformanceCounter is the way to go for duo-core processors. Unless the BIOS is buggy. The TSC (time stamp counters) are high resolution processor registers that can be used for timing.

I'd like to know why a process or thread would jump back and forth between the two integer cores and lose timing info. Yeah, I know that the TSCs are not specific to a single process or thread. Dang, now I gotta research that.

I currently have BZFlag installed from source and binary on a Core 2 Duo E6600 running Ubuntu Feisty 64. It seems that BZFlag crashes about 5 minutes into game play, sometimes more, sometimes less. I do not think that this is an issue with the dual core processor itself, but maybe an issue with 64bit. However, I have had problems in the past with the sound card and the video cards, but it seems that BZFlag should run just fine with no audio, but it does not. Currently, I've stopped playing BZFlag altogether and use the bzadmin client in conjunction with the server list over at my.bzflag.org to administer/talk on some servers. It would be great if I could find the source of the problem, because then it might be solvable.

Huh, I'm on Ubuntu 64 Feisty too. I just installed bzflag from Apt. Zero problems here. (AMD 4400+ X2 processor)

If you're installing from source, check which version of GCC you're using. I did a source install on Dapper last year, and had trouble until I pointed the gcc symlink to a 3.x version of GCC. Version 4.x gave me the "I can get shot, but can't shoot anyone else" bug.

I've used BZflag on a dual core with XP and Vista. Not one problem.

I have used a dual core proscesor, It helps decrease lag, But I have problems with UDP

charg wrote:It helps decrease lag, But I have problems with UDP

Dual Core can only *possibly* help with internal system jitter, but usually it is so minimal that you probably wouldn't notice.

UDP is NOT related to your Dual core processor, it has something todo with your firewall or router.

Ya i know, But everytime i try to shoot, It kicks me and tells me to turn UDP on , But I have no idea of what it is, or how to turn it on

Search the forums for UDP, guarantee you will find many posts on it.