Thanks to everybody for helping. oprofile has a mystifying array of possible options to log, but the -b option to top and xrestop have helped shed some light. The problem still occurs with the "vesa" driver - it looks like its the screensaver or screen locker. I'll post again when I've got it figured out. Regards John <blockquote style="border-left: 2px solid #ff0000; padding-left: 5px; margin-left: 5px">======================================== Message Received: Jan 21 2009, 12:09 PM From: "Frank de Lange" To: "John Clarke" Cc: xorg@lists.freedesktop.org Subject: Re: Xorg with ATI / RV370 sneakily eats half my CPU with empty screen? John Clarke wrote: > Dear All, > > Following an upgrade to Suse 11.1 I find that Xorg is eating my CPU alive. Here's the output from "top": > > 28834 johncc 20 0 1437m 615m 298m R 98.2 15.5 794:20.69 isis > 3103 root 20 0 748m 398m 7072 S 1.7 10.1 1080:03 Xorg > > I don't know how the massive Xorg usage gets clocked up - I never see more than 1-2% used, but nonetheless next morning there it is and my batch jobs are taking twice as long to run. > > There is no display stuff going on at all. Screensaver is now a simple black screen (although that made no difference) and the batch jobs are compute only, no graphics. Basically only the clock is changing. > > Google didn't turn up anything useful - I don't even know how to increase the logging level to tell me what Xorg is doing. > > Please help, I'm going mad. > Thanks > John Can you log in remotely to this machine so that you can observe X while it is in the screensaver? It sounds strange that you never observe more than 1-2% but it still seems to chew so much time. Maybe that simple black screensaver still makes X go bezerk... Cheers//Frank _______________________________________________ xorg mailing list xorg@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/xorg </blockquote>