CTDs when saving or zooming

[Djohaal 121]

So I'm trying to get back to SimCity but crashes to desktop are making it a hard task.

Top CTDs I get are when saving the city (sometimes losing the work up to that save) or when zooming, rotating or switching to night time. The game can run fine for long amounts of time in empty city tiles or when paused, but as soon as I start simulating it invariably crashes. I have a 60k pop city that I can't run for more than 10 minutes without it invariably crashing upon saving. I understand that with a large plugins folder crashes are almost inevitable due to SimCity being x32, but it seems I'm getting them a tad too often. 

I'm running SimCity4 on windows 10 with a sizeable 3.87 GB plugins folder.

My computer is i9 10900, with 32GB of RAM and a Nvidia GTX 970 GPU, windows version 21H1

I already:

1 - Successfully applied the 4GB patch

2 - Successfully applied sc4 fix

3 - Am Running the game via sc4 launcher (fullscreen seems to work better with wrappers), on hardware mode and with a single core afinity. 

4 - Disabled steam overlay.

5 - Attempted to run SimCity 4 trough a DirectX Wrapper - It has made rendering the buildings tolerably slower, but overall the game feels less finnicky when rotating or zooming)

6 - Set SimCity 4 to windows XP compatibility mode and run-as-administrator

8 - Correctly installed both NAM and CAM (no crashes in-game suggestible of bad plugin installation)

9 - Datpacked most of my plugins into fewer files, combed my plugins folder for detectable duplicates. 

I just had a test session by playing SimCity 4 and using the quick save (control-alt-S) which doesn't render a region picture update for the city and it seems to be able to run for longer without crashing. I wonder if anyone out there has tried something different and succeeded. 

[CorinaMarie 29,605]

The key thing which seems to be missing is -CPUCount:1.   While I don't have the Steam version, I believe that's buried in the Launch Options somewhere.

(Item 6 is worth trying, but neither of those are necessary.)

[Cyclone Boom 16,875]

Sounds good for those steps you've attempted so far.

Something which comes to mind is to add the -CPUcount:1 command to your game's startup Target line (in the shortcut after the path). This tells SC4 to only use a single CPU core, which helps with stability in preventing random crashing. See if this might help and there is an option in Steam that I recall for adding these.

[Cyclone Boom 16,875]

I see there was a special offer on today...

[Kloudkicker 4,561]

 For Steam it's SC4 Manage- Properties- General- Launch Options

[Djohaal 121]

47 minutes ago, Cyclone Boom said:

Sounds good for those steps you've attempted so far.

Something which comes to mind is to add the -CPUcount:1 command to your game's startup Target line (in the shortcut after the path). This tells SC4 to only use a single CPU core, which helps with stability in preventing random crashing. See if this might help and there is an option in Steam that I recall for adding these.

 

48 minutes ago, CorinaMarie said:

The key thing which seems to be missing is -CPUCount:1.   While I don't have the Steam version, I believe that's buried in the Launch Options somewhere.

(Item 6 is worth trying, but neither of those are necessary.)

It's been covered and already done in topic 3, I'm using a single CPU core for it via sc4launcher. I double checked on windows task manager and the afinity is set to a single core properly. Sadly I still get crashes. 

[CorinaMarie 29,605]

Ah. I missed that in item 3.

Hopefully our more techy experts will have some suggestions.

[Kloudkicker 4,561]

@Djohaal do you mind posting your config-log.txt file for SC4. Copy and paste it into a spoiler note and feel free to edit out your 'userName' and 'computerName'.

  Edited June 28, 2021 by Kloudkicker  

[rsc204 21,808]

23 hours ago, Djohaal said:

I understand that with a large plugins folder crashes are almost inevitable due to SimCity being x32, but it seems I'm getting them a tad too often. 

No that is a total myth and my many years with the game on many different systems, have proven to me again and again that whenever you get CTD problems, it's always something wrong that can be fixed.

23 hours ago, Djohaal said:

6 - Set SimCity 4 to windows XP compatibility mode and run-as-administrator

You should only set this if it helps overcome a compatibility problem, the game actually runs better if NOT set to use any compatibility modes, although Run as Admin is best kept on.

23 hours ago, Djohaal said:

5 - Attempted to run SimCity 4 trough a DirectX Wrapper

Unless there is a direct incompatibility with your GPU, wrappers won't fix CTDs and again I would advise not using such unless you need to, they only gum up the works. If your hardware can't support DX7's DDraw modes, you should also get an error and the system will switch to software rendering automatically.

23 hours ago, Djohaal said:

or when zooming, rotating or switching to night time.

I hate to say it, but that is classically what you'd expect if the single-core CPU command wasn't being invoked. I know you checked the affinity, but given what you are saying, it'd be remiss of me not to at least suggest it's worth a double-check.

23 hours ago, Cyclone Boom said:

Something which comes to mind is to add the -CPUcount:1 command to your game's startup Target line (in the shortcut after the path).

That's the more reliable method over using a launcher IMHO.

Outside of the above, the way I see it you must have one of two potential problems. The first is that somewhere between your GPU, it's driver, Windows and Direct X your system is having compatibility issues using the legacy DirectX modes SC4 needs. The second is that the problem resides within your Plugins folder, which is thankfully very easy to check. Temporarily remove all of your Plugins and load the game without any mods, you may have to play for sometime to be sure if it works stability or not. Only once you've ruled out any mods interfering with things, would I move to some more advanced GPU-related configuration. A copy of the config-log is probably useful as mentioned above.

Lastly, having mentioned Software Rendering, games include this option which essentially makes the CPU do the job of the GPU, but should work on all systems regardless. I would recommend also trying the game with Software Rendering, if the CTDs stop this is a clear sign of a Direct X related problem. But if they don't stop, it suggests the problem does NOT come from your Graphics setup.

If it helps any I've a GTX 960 which when I was still running Windows 10 worked flawlessly with SC4, in General NVidia desktop cards are usually fine. But it couldn't hurt to try and find the oldest driver you can get hold of, to see if the game works better with that. Certainly, from the problems we're seeing it seems like both NVidia and ATI have changed things that affect legacy DirectX support, although it mostly affects newer RTX and 10 series cards.

[Djohaal 121]

Yes I should do a test by removing all plugins and running a dummy city for a while to check if it crashes. Speaking of the directX wrapper, while it hasn't solved my crash issues with saving, it seems that crashes related to rotating and zooming have improved by using a wrapper. The game runs a bit more slowly, yes, but it feels less finnicky and smoother.

[Djohaal 121]

Self-bump (I'm not sure if a post edit would be updated for those following the thread). I don't know what I did that fixed the CTDs, but it was most probably either running simcity4 in administrator mode or using the DirectX wrapper (my hunch it was the wrapper).The game does run a bit more slowly with the wrapper, but I notice its much cleaner and stable when loading models, what I think was one of the common triggers for the CTDs.

The only consistents crashes that remain are when doing a regular save or sometimes when quitting to region view, however the quick-save (control-alt-s) function seems to rarely crash, if at all, so I usually employ quick saves and when I'm done I try a regular save just after quick saving so the region picture updates. 

[CorinaMarie 29,605]

19 minutes ago, Djohaal said:

Self-bump (I'm not sure if a post edit would be updated for those following the thread).

Good idea for a new post as an edit does not notify anyone.

 

19 minutes ago, Djohaal said:

The only consistent crashes that remain are when doing a regular save or sometimes when quitting to region view,

The Save and Exit as well as the Save and Quit options are both buggy after a certain level of complexity is achieved in a city tile. It is recommended to never use these options. Instead use the Save option separately, then Exit or Quit without saving.

[Djohaal 121]

4 minutes ago, CorinaMarie said:

Good idea for a new post as an edit does not notify anyone.

 

The Save and Exit as well as the Save and Quit options are both buggy after a certain level of complexity is achieved in a city tile. It is recommended to never use these options. Instead use the Save option separately, then Exit or Quit without saving.

Yeah I read about that, I never use save and quit/exit. But the crash when just "exiting" to region view still happens. 

[rsc204 21,808]

6 hours ago, Djohaal said:

But the crash when just "exiting" to region view still happens.

This is usually something that happens when your save file becomes corrupted, out of the 100's of cities I've made over the years, I've only had this occur with 3. 2 of which I'm as certain as one can be, were caused by using Save and Exit or Save and Quit, something I've long since avoided doing.

The third city is one where I probably screwed something up with all my modding activities, I've had to restore it from a backup a couple times. It is not well understood what the effects of changing the contents of your Plugins folder has on existing cities/save files. Generally speaking adding new content doesn't lead to problems, but changing or removing anything from your Plugins folder, that exists in your current save files is best avoided. Before you make such changes you should first remove all instances of the content you are changing from every affected city. The game was never designed to handle the sorts of things many of us are doing and this can if you aren't careful, lead to problems.

Once a given city starts giving these CTDs on exit, there is no way currently to fix the savefile. So it's important to keep regular backups, that way if something does go wrong you can at least restore a working save. The good news is that other than the CTD, you can still save progress (best done using CTRL + S) and continue using the city. But if you are finding this problem keeps coming back, then I would suggest you review how you are altering your Plugins folder, because that's almost certainly the root cause of such problems.

[Djohaal 121]

Alas I might have fallen victim to confirmation bias.

The moment I tried to move up from mostly farms and into a large city tile with a significant population (about 170k sims, and 80% ish coverage of the large tile) the crashes when saving reappeared. I can't get even 10 minutes of game in a city without it crashing when saving, even if I use the "quick" save function.

I did a test with a "clean" SimCity, that is, no plugins at all (other than sc4fix and extra cheats). Managed to push to a 250k test city with zero issues, what leads to the conclusion that -something- in my plugins folder might be the culprit. Now for the ten million dollar question, how do I even begin troubleshooting such an obtuse error?

EDIT: So the plot thickens and this soap opera never ends. It seems I might accidentally have clicked the set to default option in sc4launcher, giving SimCity a very unstable access to all my 20 cores. I rolled it back to one core and the cursed city ran fine for some 20 minutes and saved without crashing. Stay tuned for more thrilling and heart-throbbing updates in Djohaal's misadventures with an awfully old piece of software. 

[Cyclone Boom 16,875]

20 hours ago, Djohaal said:

Now for the ten million dollar question, how do I even begin troubleshooting such an obtuse error?

For this one way forward is to apply the binary method for identifying plugin conflicts or issues.

It is a time-consuming process, but involved dividing one's Plugins into halves and further halves until the problem is no longer present. For what you're experiencing though, it might take a while of playing each tile before being able to reproduce or rule out the issue.

How you've checked the launcher settings to make sure the game only runs on a single core does sound encouraging though. So hopefully that fixes it for you.

[Djohaal 121]

Ok so here we go on more testing.

1: Multiple cores: Stability did improve significatively when setting SimCity to a single core, however from this post you can imagine it wasn't enough.

2: DirectX Wrapper: A must from my testing, while SimCity does run a itty bit slower, it is the only stable configuration I managed to use, if I remove it I start getting some very nasty sprite errors in large city, and the game crashes less than 5 minutes in. So it might be an educated guess that for up to date nvidia drivers you need a directX wrapper.

3: Datpacking: Datpacking very file intensive collections seems to improve in-game stability for me, alongside with loading times. I've managed to datpack the NAM with no errors and the game seems to run a little faster.

4: Region size: Another confounding factor that I realized now is the region size I'm playing. I'm using a humgous 20x20 large city region, I wonder if poor optimization in the region menu might be leaking memory and making me start off in a bad footing so crashes are more common. I'll try testing this later by isolating one of my crash prone cities and testing it in a standard size region.

5: Stability, city size and camera: I'm noticing two clear trends with instability in SimCity. First is the overall ammount of "stuff" going on in a city. My rural cities are pretty much crash free and I can play for long bouts of time. However I'm encountering far more crashes (up to one every 20 minutes) in my larger 400k pop large city tile. Tied almost directly to it seems to be camera usage. The more I zoom in and out, rotate the camera or flip between aboveground and underground views, the faster performance degrades. After a few times in a large city tile it seems the game enters some corrupt or unstable state where fps gets choppy even in a fully-loaded zoom and while paused. Almost inevitably in this state a quick save ends up in a CTD, or even if I leave the game running for longer after this starts the game ends up crashing.

[Lazarou Monkey Terror 1,819]

I'm getting the same problem when saving "busy" large tiles. Muscrow has over a million sims. 

Also, after a successful save if I don't clean my RAM repeatedly the game freezes and CPU usage goes down to 0

I'm on Windows 10 and these are my launch parameters. 

 

[CorinaMarie 29,605]

@Lazarou Monkey Terror

While this won't help with your current problem, you might be interested to know as far as we can tell the -CPUPriorty:high prolly doesn't do anything useful. See my post here and then a follow up two posts later in the same thread.

[Lazarou Monkey Terror 1,819]

I see " -CPUcount:1" being mentioned upthread. Would that be better? 

[CorinaMarie 29,605]

2 minutes ago, Lazarou Monkey Terror said:

I see " -CPUcount:1" being mentioned upthread. Would that be better? 

Yes, that one you always want to include.

[Cyclone Boom 16,875]

8 minutes ago, Lazarou Monkey Terror said:

I see " -CPUcount:1" being mentioned upthread. Would that be better? 

Just adding to what Cori confirmed...

This command line option is very important for stability on modern systems. It instructs SC4 to only use a single CPU core which ensures the game runs smoothly. Otherwise frequently CTDs can occur, which is due to instability caused. The SC4Fix is recommended too, which helps prevent other crashing.

[Lazarou Monkey Terror 1,819]

Thanks Admins! 

Just had a successful save, let the game run for a few decades, minimal scrolling and no building and it behaved. 

But the next time it crashes I'll update my launch parameters and see where we go from there. 

[rsc204 21,808]

2 hours ago, Lazarou Monkey Terror said:

But the next time it crashes I'll update my launch parameters and see where we go from there. 

The -CPUCount:1 is not optional, this is because SC4 was designed in an era where multi-core CPUs didn't exist. From Windows Vista, the OS will try to force multi-core use, whenever an application uses more than one thread, it puts them on different CPU Cores, trying to make things faster. The problem with SC4, is that those threads must be in sync, but when you put them on different cores, that doesn't always happen. No code exists to make one wait for the other (so far as I can tell, it's only ever 2 total), so if they get out of sync, you get a CTD. Most commonly this happens when scrolling or zooming, but it just generally makes the game unstable. This command tells Windows, only use one Core, as soon as you do that this problem goes away. Add the SC4Fix.dll and there is no reason why you should suffer random crashes, SC4 can be rock solid stable if setup properly.

3 hours ago, Lazarou Monkey Terror said:

I see a few commands that honestly make no sense to the average player.

-Cursors:fullcolor
-d:DirectX

Both of these commands invoke the default settings, you'd only need them if you had changed the defaults. Many of these settings actually lead to a permanent change to the game, once invoked the command isn't needed any more either.

-CPUPriority:high

This does nothing, you can verify this by looking in Task Manager, where the SC4 Process isn't set to high priority. I think changes in Windows prevent it from being passed to the OS, but it's also a complete myth that this is in any way beneficial. Unless your computer is under heavy load elsewhere, Windows will give SC4 every bit of power it can, just like how your computer won't enter standby with a game running, it knows not to use energy saving modes when a game is running.

If I were you I'd remove these unnecessary settings, if for no other reason for the sake of simplicity. There is a lot of bad and misleading information out there with regards to which commands to use. A few should be used by everybody, but most of these are only needed for very specific purposes, someone who says "add this command" but fails to explain why, probably doesn't understand what they are telling you.

[Lazarou Monkey Terror 1,819]

Aww Poo, crashed after saving even after I changed the launch parameter.

Now trying it without "Background saving", perhaps the save file won't be so big? 

 

[Lazarou Monkey Terror 1,819]

3 hours ago, Lazarou Monkey Terror said:

Aww Poo, crashed after saving even after I changed the launch parameter.

Now trying it without "Background saving", perhaps the save file won't be so big? 

 

Nope, that didn't make a difference 

[Lazarou Monkey Terror 1,819]

Ugh, still no progress.

For the record I have tried;

• tried a neighbouring square of comparable size 
• compatibility with; Windows 7, Windows XP SP3 & SP2
• No compatibility  
• CPU count to one 

I'm still thinking it's a performance issue but could it be a plugins conflict?
I note in a similar thread Mitsos solved their large city save problem by finding an errant file. 

[Lazarou Monkey Terror 1,819]

Currently working on datpacking and organising my Plugins Folder, research suggests this is the way forward for a more stable game. 

I also found this post which is very similar to my situation and contains some possible solutions https://community.simtropolis.com/forums/topic/69461-show-us-how-you-manage-your-plugin-folder/?do=findComment&comment=1601609

[Lazarou Monkey Terror 1,819]

22 hours ago, Lazarou Monkey Terror said:

I also found this post which is very similar to my situation and contains some possible solutions https://community.simtropolis.com/forums/topic/69461-show-us-how-you-manage-your-plugin-folder/?do=findComment&comment=1601609

"touch wood" but I've been having successful saves all day thanks to this technique!