task switching under rendering

(endi) #1

I have problems with task switching when Blender rendering. Sometimes the render stops, sometimes works, but the screen is not updating.
Why? Can anybody help?
Win98+GeForce2 MX 400

(rwenzlaff) #2

Since rendering is such a high CPU user, Blender kinda’ assumes you really want the render done and and it hogs the CPU.

The problem is, sometimes other apps assume you want THEIR work done and do the same.

Windows 9x isn’t a preemptive multi-tasking environment. Windows can swap tasks whenever the it’s in charge, but that’s only during system calls (cooperative multi-tasking). Most apps call these system calls very frequently, so it gives an illusion of smooth multitasking. During Render, Blender doesn’t make alot of these. There’s almost nothing Blender need from the OS at that time, and it assumes that render has the highest priority. There are ways to make this smoother, but at a cost of speed.

Unix and NT are preemptive Multitaskers. There’s a timer interrupt that can cause a task swap at any time.


(S68) #3

And both these permits you to renice Blender (or something else) so that they run on a low priority :slight_smile:


(kattkieru) #4

This is all true, but Win98 should be able to run command line blender renders and whatever else you’re doing at the same time (as long as the other things aren’t too processor intensive). Try doing renders from the command line in a console window… erm, in a dos prompt window. It should help.

The other option is to upgrade to Win XP or a real OS like Linux or Mac OS X. :wink: