I'm not so sure this is a problem with OllyDbg so much as with Windows, but I've been unable to find anything on the net so I thought I'd post here.

I've experienced system wide performance degradation while running OllyDbg. It's always when I have the same thing loaded, and code is executing in a certain DLL. I think it may be breakpoint related. I've set a breakpoint on some code which I'm sure should be executed, but rather than stopping at the breakpoint, my whole system just sort of freezes up. I can still switch between programs and use Task Manager to close OllyDbg but it takes about 5 to 10 minutes to do so. I get the same slow responsiveness from the whole system even though Task Manager reports only about 10% of the CPU is being used.

I'm quite sure the problem is related to running OllyDbg as the problem is fairly consistently repeatable. Closing OllyDbg always makes the performance issues go away, and closing other programs has no effect. I should note though, that sometimes I can get a breakpoint to fire as expected, but once the problem occurs, it tends to stick around until I restart. Unfortunatly, restarting doesn't seem to help the problem as of late.

I'm running WindowsXP SP2 and OllyDbg 1.10. And if it helps, the DLL being debugged should have just received network data at about the point where the problem occurs.

look in the services task list maybe a service is altering the ollydbg work (there are services hasp, securom,etc with antidebugger), of maybe the program detect the BP and make loops for use so much CPU.

Ricardo Narvaja

Well, I've toyed around a bit more. If I remove all my breakpoints, I don't get this problem. However, the program does still pause on me because of a Single Step Event. I seem to be getting these at random. Perhaps one is setup as a conditional/log breakpoint? That might explain the performance loss, yet me still getting no indication that anything has happened. Of course, I still don't see why I would get a system wide problem rather than just OllyDbg and the debugged program running slowly. I haven't seen any running tasks that I'd think would interfere here.

What strikes me as odd about the single step event, is that I never did anything to cause it (that I'm aware of). I went through a fresh run, closed down OllyDbg, came back, and ran it again, and it stoped. I seem to get this happening at random. The location changes too. The last two I've experienced were one instruction after a log breakpoint. I'm going to check to make sure they aren't causing the performance problems, but I suspect if they were, the problem would never go away like it sometimes does.