Half-Life 2: Episode 1 Forum

Okay, so Episode 1 installed and loaded up well enough. I didn't even need to tweak any of the launch options beyond adding my usual "-window". After playing through it a short way, and reaching a certain point, I start experiencing massive slowdown when I am in the general vicinity of the next room I'm supposed to go through. I haven't actually played Episode 1 before, which is why I'm being so vague--I don't actually know what's in that room that's causing me to lag so much.

I've recorded a short video showing how it starts lagging up unplayably when I approach the room, and if I hold onto BACK, I can manage to get away and start moving normally again:

http://www.youtube.com/watch?v=fRs2kdyabhw

Other details: I'm running this on a 2.5GHz Macbook Pro, with an nVidia Geforce 8600M GT, 512M video ram. Running OSX 10.5.2.

I've tried using -dxlevel 81, and -dxlevel 80, and both experience the same problem. I cannot reach the title screen if I use -dxlevel 70.

I have had success playing Portal (from start to finish), and Team Fortress 2 with no problems (apart from mouse lag, grr), and Episode 1 was playing fine up until now (apart from mouse lag, again, grr).

So, anyone else played this through and experienced this issue, or got any ideas how to fix it?

An update:

cl_drawmonitors 0

managed to get me through the room. I hope there was nothing interesting on the monitors there. (c:

The semi-transparent light beam in the reactor room that is displayed on the monitor makes the problem. I think I had a hack in our StretchRect code to ignore this backbuffer to texture copy since the game does it incorrectly anyway. Seems that it doesn't work as intended any longer. Maybe HL2 changed...