Where is the Kill Switch?

Recently Blender has froze on me several times. And, yes the last time I was in sculpt mode with multiresolution and had hit render. The ‘Stop This Job’ X had no effect and of course Esc won’t do it. I attempted to close the program from the desktop and taskbar but that didn’t help. More attempts with the ‘Stop This Job’ button followed until finally I lost the mouse all together and had to simply shut the computer off which I understand just drops the HD and we all hate to resort to that. Oh and I forgot to mention ‘Task Manager’ wouldn’t even come up.

Is there a key on this Microsoft board that will close Blender when frozen? I have a AMD processor if that’s of any use and Windows 7 is the operating system. If not can the developers address this problem with a Kill Switch that works every time?

The X is the kill switch. So the developers have already given you that option.

Maybe your project is too big for your machine? But without seeing your machine specs or BLEND file who can know? Which render engine were you using? Are you overclocking your system?

It sounds like Windows locked up while Blender was running. Perhaps ask on the Microsoft forum for developers to make an OS that does not do that.

Without a doubt the render was obviously to big for the system. Sculpt Mode with Multiresolution? Like I’m the first one this has ever happened to. Blender stopped responding and then Windows locked up or Windows locked up and then… I care not what happened first since it happened because Blender was asked to render a scene and evidently Blender is not user proof. Nor would I expect it to be. But, when it happened the ‘Stop This Render’ button was useless. Since my system has never locked up except when using Blender I have no reason to be visiting a Microsoft forum. Nor do I like Linux.

Let me rephrase the damn question. When Blender is open and the system (Windows 7) stops responding, for whatever reason, is there a key on the keyboard to resolve this without shutting the computer down from the power button on the tower?

Yes, the X button does that. It’s rather difficult for it to gracefully kill the render job if the system is out of memory because you rendered with too many subdivisions. (if you’d rather ungracefully stop, kill the blender process)

This is actually largely a Windows problem, on Linux or OS X usually it’s simple enough to nuke a memory hogging process from the GUI, although you might need to wait on some laggy apps for a few seconds. It only seems to be Windows where people complain of the whole OS grinding to a halt because some process asked for too much RAM.

It isn’t possible for Blender to know how much is too much RAM on a given system, and provide a warning when it starts to get close to the limit, or is about to perform an operation that has big chances of going over the limit?

@J_the_Ninja Thanks for the explanation. So it’s windows users beware when using multiresolution in sculpt mode. Actually, it might have come around but I’m sure all six cores were clipped at 100% percent. So it comes down to how long are you going to let that play out or go for the power button. Nah it wouldn’t have righted itself. @Tiago Tiago So it isn’t possible for Blender to be dummy proof. I copy that and will just look for the signs in the future.

I might’ve messed the grammar a bit; that was meant as a question, not a statement.

@J_the_Ninja Thanks for the explanation. So it’s windows users beware when using multiresolution in sculpt mode.
Not just windows. On OSX programs can also bring your machine to a grinding halt

When I read this, my first reaction was that it’s likely to be an out-of-memory situation.

On my old laptop with 2GB RAM, as soon as any app tried to use more than 700-800mb, the system would indeed start to lock up as Windows starts “swapping” (i.e. the performance killer). In such situations, it is practically impossible to do anything with the computer - heck, in some bad cases, the cursor even stops responding completely for up to 5 minutes until whatever it was has completed it’s business (in my case, it was usually Windows Update searching for updates). From what I can tell, it’s probably likely that the lockups occurred because Windows ended up swapping out system processes as well (!), including the display manager.

Anyways, back to your specific situation: sculpt + multires can result in high-memory usage situations. While the multires mesh in and of itself might not be a problem while working on it in the viewport (though it may be getting close), Blender will need to create a second copy of it (albeit, in a slightly different form) that the renderer uses. The combined load of both of these together probably requires more memory than you’ve got on your machine.

Since these freezes do occur and when they do they can become unable to be stopped, the best course of action is to be able to predict when this is likely to happen given your setup. Firstly, you’ll need to know how much RAM your computer uses post-startup (with just the background stuff). Based on that, you know the maximum “working memory” the computer has before it will start swapping. However, from experience, the actual threshold before it starts swapping is perhaps something around 50-75% of that maximum capacity.

Additional things you can do when you anticipate that you’ll be doing something memory intensive:

  • kill anything non-essential, and then some more if you can kill them without bringing down the system (and/or the system lets you).
  • try starting Blender from the command prompt instead, and issue Ctrl-C twice in the console you used to start Blender with when it starts locking up. This sometimes works (though not always, since you might not be able to even change windows by that point), but it should be slightly more responsive than the Blender GUI when things lock up