Maybe you should concentrate more on your objectives than on running in circles slaughtering everything that moves.

Maybe if I could walk down a hall for more than five seconds without being attacked, I could concentrate on the objectives.

Are there any /helpful/ suggestions?

from what i understand monsters usually spawn when the population on the level drops below a given number.
Also they can spawn in response to objectives that you complete

I'm with you here, respawn-rate seems very high, especially since those monsters you mentioned don't give you back anything and hence you keep running out of ammo very soon which is very frustrating.

Okay, I just installed System Shock Classic Edition and loaded the save-games from EE in the older version (save games are apparently compatible between Classic and Enhanced editions).

After clearing out the backlog of respawned monsters, new spawns are down to a managable level; maybe one new critter every few minutes. This is high for a modern game but more or less what I remembered from last time I played the game.

As I said, my test is simple: I just run around the main loop of level 3 until a monster spawns (this isn't how I normally play, just how I've tested the bug). In the Enhanced Edition, a new monster will spawn by the time I make a single loop. With Classic Edition, I'll make ~10 loops before a new monster (an invisible mutant) starts attacking me.

I haven't done as conclusive a test with the other levels (if only because I don't have save games for the other levels and I do not intend to play Classic Edition any longer than I have to; I like EE's improved graphics and WASD/mouselook controls too much ;-) but respawning on the Hospital Level and Reactor level (but oddly enough, not the Research level) seemed excessive as well. So I think this is a real bug and not just my being spoiled by more forgiving games.

One of the difficulty settings you choose at the start probably affects respawn rates, too.

That still wouldn't explain why the same save game has different respawn rates when tested on the Enhanced Edition and Classic Edition games.

Not trying to explain it, just presenting one more piece of the puzzle to consider. : )

I also think the monster spawning is different / bugged on the EE compared to the classic, although there may be some conditional factros involved. I *think* that depending on the objective you are trying to complete, there may be (different) trigger points when monsters will be spawned (somewhere on the level).

For example, on the reactor level, II had forgotten where to get the ENG access. I was looking for it, and kind of bouncing between the recharge station, and surgical bed. Somewhere between these points there is a trigger point which will cause a bunch of hoppers to be spawned. Normally - if the player had the ENG card, this would not be an issue since the player would use that access, and walk trought the trigger point just once. But not in my case, as I was bouncing trought the level trying to find the access card (which is not there)...

However, I still don't remember the original would spawn this much monsters on the same difficulty. Perhaps walking over a "trigger point" should spawn monsters, say 20% of the time? Or, it could be just time-based after all (but the spawn points just being fixed).

I knew it wasn't me. Those bloody Hoppers are ridiculously hard to kill already without using a ton of ammunition on them...

Or one swipe of the laser rapier.

Well, I never liked using melee.

I also got a floor covered on invisible mutants but it was because I stayed too long in there. After that I learned to sprint from elevator to elevator or from elevator to the cargo elev.
Also Rapier is extremely effective with the poor slimes :P and the hoppers too.

I must agree. I just played SS:EE and the Hospital level got SWAMPED with mutants. I fought four mutants in the main loop (inbetween the quadrants) then ran to heal in the hospital (where you start), four more mutants. I come out into the main loop area again, four more mutants.

12 mutants in the span of maybe 2 minutes. What the heck? It's insane. I know the original game had a fairly decent respawn rate (because I've played through that) and especially on level 3 (those damn invis mutants spawned the instant you killed one. They had a set population. Really annoying) but I don't remember this insanity on the hospital level.

Now granted, I'm on the hardest difficulty, but even then it's just bonkers. I wonder if it's some kind of timing that got thrown off in the conversion? So that the respawn logic is running way faster than it's supposed to?