As I've been making my map, I've been testing it at regular intervals. When the map was finished, except for a couple of tunnels that needed lighting, I tested my map, and everything worked perfeectly - no problems at all.

I added the last few lights, just like this one. They are just textured brushes set into the wall. Yet placing these lights in a small area of my map, has now caused lag throughout my map. About half the time the map plays at normal. The rest of the time, the map can go down to speeds of only 10fps

My map was already fully optimised with hint brushes, areaportals, and all possible brushes were func_detailed, yet my map was lag free until adding lighting to the tunnels. Removing the lighting is a no-no, as then it would be too dark for the player to see. There are no leaks in my map.

http://i26.photobucket.com/albums/c113/megadude2006/journey/lag01.jpg

The tunnels are at the bottom right part of the map in the above pic. To give you an idea of the size of the map, the metal squares you can see at the top of the pic are the largest metals ones used.

Does anyone have any idea how work on a tiny piece of a map can lag the entire map, or how it can be solved?

Have you tried playing the map with "+showbudget" enabled?

When the lag kicks in, you should get some pretty obvious feedback as to what is causing it.

It showed the causes as Sound and Steam, which is weird since Steam has never caused problems before, and I don't have any sound in my map except for a couple of sparks and the occasional GLaDOS voice., which didn't cause problems in earlier tests.

Now to add to the problems, the more times I load up this map, the laggier it becomes

When you say "Steam" you mean steam coming off of your goo or what?

I mean Steam as in the Steam engine/package. However, upon doing some more investigating in my map, the +showbudget values showed Steam and Sound to be back to normal. I know that Steam was playing up a bit for myself and quite a few other people, so that may have been the cause of the lag. Since Steam seems to be working normally today, the lag seems to be gone

I'm also experiencing that kind of problem with Steam. It makes my maps laggy, but I noticed that Hammer was the culprit. I'm playing in windowed mode, while Hammer is still running in the background. Looks like if Hammer is not entirely REDUCED in the task bar, it consumes CPU time. I did this for over a year without any problem, it doesn't seem to be possible anymore.

Phew At least that confirms the lag isn't my fault

If the Steam budget is way high, it's likley due to some sort of update in either the Steam Client and/or Source engine code. I would suggest emailing a screenshot of your +showbudget screen and your BSP file to Mike Durand, the SDK programmer.

msleeper wrote:

I would suggest emailing [...] Mike Durand, the SDK programmer.

The same Mike Durand that never answered any of the e-mails I sent him in the past? I don't think it would help much unfortunately

Either you're not sending to the right email, or your email didn't require a response. I've emailed him dozens of times, sometimes he responds, sometimes he doesn't. I would imagine he gets hundreds, if not thousands, of messages a day so I wouldn't get to butthurt if he doesn't respond to every single one.