Weird: turning the profiler ON gives me dramatically better performance

[Volnaiskra]

I'm stress-testing my enemy engine, so I added 150 enemies to my level, and enabled the 2.5+ profiler. When I run it, I get max fps (120fps). The game seems to work correctly, everything seems fine. When I quit, the profiler window pops up with the results. So far so good.

Then, I turn profiling OFF, and re-run the MFA. This time, the game slows down to a crawl: 25fps.....huh?

I feel like I must be missing something really obvious, or else am going mad. I repeat, turning the profiler ON makes the game run beautifully and smoothly (with everything working fine, as far as I can tell, at least at a glance) , while turning it OFF makes it a sideshow.

Is there something that the profiler might somehow be disabling or throttling, that could artificially inflate the performance?

[BartekB]

The first thing that comes to mind is the debugger. When toggling the profiler on, it is disabled so it won't affect the results. Depending on the project, you may have add to debugger, send text to debugger, etc. Other than that, I don't have much more information on how the profiler works or what other things it changes.

[Volnaiskra]

.....you may have add to debugger, send text to debugger, etc......

As usual, you're right. Thanks!

Surprisingly, the culprit was a Run this event once event, yet it caused continual slowdown. This event added 150+ enemies to the debugger, which is obviously an awful lot. But still, the debugger was turned off, so I'm surprised that this could have such a large performance impact. (turning the debugger on dropped the FPS further, from 25 to 9).

Anyway - Phew! I'm really glad that the true performance figure was 120 rather than 25, even with 150 enemies.