Blender jumps to 99% CPU usage, slows computer horribly

This used to happen once every few days but now it happens several times a day, and I can’t figure out what’s causing it. At apparently random times, Blender will suddenly slow down incredibly, along with the rest of the computer (except the mouse cursor which moves normally). I can still press keys and click things but the computer takes 5-30 seconds to respond to each action.

I have an AMD Athlon 2000+, 512mb DDR-RAM, ATI Radeon 7000 64mb, and Windows XP Pro. I am using Blender 2.4. I never had this problem in 2.37.

What I’ve been doing is pressing Control-Alt-Delete, waiting for the Task Manager to come up, clicking on Blender’s process (which always shows 99% CPU usage), waiting for it to actually highlight, and then clicking End Task, waiting for the confirmation window, and then clicking yes. Within five seconds of clicking yes in the confirmation window Blender closes and everything returns to normal, but getting to that window takes as long as two minutes. It’s extremely annoying and has almost cost me my work several times.

I can’t figure out a solid pattern but some things are similar between the freezes. It always happens while I’m doing something with the mouse - clicking, using the scroll wheel, or just moving the cursor around. It happens half of the time in the file navigation windows (usually Open File) and half of the time while working. I’ve never lost more than a minute of work to it because when it happens while I’m working it’s usually shortly after saving.

I’m pretty sure it is your ati card. Try updating the driver to the latest version and/or turning down your opengl graphics accelleration settings.

If you’re on 2.4, maybe get 2.41 see if that helps

The latest ATI drivers don’t work on my computer. I have the Blender ATI .dll fix (the old .dll in the Blender folder).

I don’t see how the video card would cause it to suddenly jump to 99% CPU usage. I’ve experienced the ATI problem before and Blender just slows down gradually, but it doesn’t take the rest of the computer with it.

edit: I downloaded 2.41, I’ll see how that goes. It seems to be running smoother, but that’s probably just my imagination.

It still happens in 2.41. 2.41 also has one of the glitches that was removed in 2.40 - if I have two 3D windows, the Open File window opens in the Button window instead - extremely annoying.

Based on my own experience and what I’ve read in this forum, it’s most likely the ATI card. I ended up switching out the graphics card. But I’ve read a few threads that discuss a driver related solution to this problem.

Strangest one: Instead of the latest ATI drivers, renaming an nVidia .dll placed in Blender’s root folder helped some people.

Try a quick search.