X3:R "target switching/cycling" crash (and other generic random CTDs) potential fix - framerate limiter

[Lwerewolf]

As the title says.

I found out that on two of my systems:
1 - 5800x, 5700xt, win10
2 - 8770w, 3620qm, gtx780m (yes, modified), win7 & mint 18.3 (old system, haven't touched )
...X3:R would crash when rapidly cycling through targets, no matter the OS, graphics settings (key point - didn't try vsync, I always keep it off) or whatever else I tried. I was playing XTM at first and originally blamed it on seeing a centaur mk3 up close but then tried and actively reproduced this on both the Steam version of X3:R (v2.5a) and the Superbox installer version (v2.5, 2007-ish?) (on the 8770w, still has a DVD) and the same thing happened - new game, start cycling targets and bam. Anyways, tons of threads here and elsewhere that describe this particular behaviour.

I decided to try it on my SP3 (i5-4300u) since it is relatively old and has integrated graphics only and...
...nothing.

I then used rivatuner on my desktop to limit the FPS to 60 and tried to reproduce this - again, nothing. Vsync should have a similar effect (and might explain why a lot of people don't have issues).

I've played X3:R for close to 4 hours without a crash on my main PC, locked at 144fps (matching the monitor refresh, not quite optimal for tearing but not noticing any) and... nothing. Bonus point - no coil whine from the GPU running with furmark power consumption in the main menu

Anyways, couldn't find any references to this having been found before, so here it is. From what I've been told (@Alan Phipps), newer X3-engine games have an FPS cap by default - I guess it explains the lack of these random CTDs manifesting. Might be a good idea to implement this for X3:R as well?

Some threads with (I think) the same thing:
viewtopic.php?t=255428
viewtopic.php?t=298103
viewtopic.php?t=325428
viewtopic.php?t=331306
viewtopic.php?t=337665
viewtopic.php?t=355146
...discussed on steam as well.

[Aceridus]

I can confirm that I also see a crash to desktop when rapidly cycling through targets in X3: Reunion. It is very quick to reproduce in the Simulator on Combat Test Level 1. It happens on the following two machines:

1) Windows 11 with an RTX 3080 Ti. Here is the 'General' tab info from Event Viewer after the crash:

Code: Select all

Faulting application name: x3.exe, version: 2.5.0.1, time stamp: 0x515f0302
Faulting module name: x3.exe, version: 2.5.0.1, time stamp: 0x515f0302
Exception code: 0xc0000095
Fault offset: 0x00007a2d
Faulting process id: 0x2acc
Faulting application start time: 0x01d85616ce8574dd
Faulting application path: C:\games\Steam\steamapps\common\X3 - Reunion\x3.exe
Faulting module path: C:\games\Steam\steamapps\common\X3 - Reunion\x3.exe
Report Id: cde38f11-dda3-40ff-ba3a-006d1990615b
Faulting package full name: 
Faulting package-relative application ID:

2) Ubuntu 20.04.4 LTS with a Radeon RX 5700 XT. I see the following on dmesg after the crash:

Code: Select all

[ 4393.125456] traps: X3R_main[604304] trap divide error ip:8175474 sp:ffbd6b5c error:0 in X3R_main[8048000+1e4000]
[ 4442.358346] traps: X3R_main[618478] trap divide error ip:8175474 sp:ffd4439c error:0 in X3R_main[8048000+1e4000]

Based on the dmesg output it sounds like an elusive divide-by-zero case.