I stumbled across a post here: http://forum.1cpublishing.eu/showthread.php?t=8672, and decided I was sick of all these links 404ing.

I decided that I may as well make the adjustments mentioned in that post, since Megaupload went down. I think I've fixed the majority of the performance issues. I changed two files: The config.cfg file in the root folder for the game, which should be located under Program Files\GOG.com\Cryostasis\config.cfg. The other is init.cfg, which can be found under Cryostasis\Data\Scripts\init.cfg. I recommend that all edits be performed in notepad, and NOT with word or openoffice, because they'll tack on useless junk that'll keep the game from reading the file properly.

Back up both of those files before you make these changes.

First, you need to locate notepad. If you can't do that, don't make these changes.

Right click and launch notepad with administrative rights. Both of these files require administrative permissions to edit, and you'll get a bunch of 'could not save' errors if you do this without administrative rights. There are other ways to do this, but this is my preferred method. Note that this requires you to navigate to files using the file -> open menu on notepad, rather than with Windows explorer.

Navigate to Program Files\GOG.com\Cryostasis\config.cfg and open that file. Make sure you've backed it up before continuing. Delete all the text in that file, then copy and paste this: http://dl.dropbox.com/u/18067260/config.cfg into it. This puts every option to the absolute lowest possible setting. If you feel capable, make whatever changes you want. Again, back everything up first. Then save.

As a brief rundown, these are the changes I made:

Resolution at 640x480 (@v.sx is X resolution, @v.sy is the Y resolution. Change these as you see fit)
Cloth and fur rendering disabled.
Water environmental and entity reflections disabled.
Postglow and caustic rendering disabled.

These are purely graphical changes, and I don't think it's possible for these to break your game. Just restore your backup if you have issues.

Second, the init.cfg file. This is hidden a little better than config.

Open notepad the same way as before, and navigate to Cryostasis\Data\Scripts\init.cfg. Open 'er up. Back up this file, because it can break your game if it's edited incorrectly. Back it up twice. Maybe three times, and keep a copy on a flash drive. You'll have to reinstall the game if this gets broken and you don't have a backup. Nobody wants that.

Same deal as last time, delete everything. Copy this file: http://dl.dropbox.com/u/18067260/init.cfg, and paste the contents.

I have not played through the entire game with this file. I can confirm that the first fifteen seconds of the game work with this file, but no promises about the rest. This will make sections of the game that take place outdoors a little wonky, especially the black and white sequences in level one. Be prepared for that. It won't affect gameplay, just the lighting.

It is possible to make sections of the game unwinnable by disabling items, so I left those in. Feel free to disable this yourself, and then re-enable it when you reach those segments. Change r.showitems=1 to 0 to disable them, and then back to 1 when you need them again. Be careful, because this is very capable of breaking your game and forcing you to restart from level one.

If you feel confident in your abilities to edit this thing, go ahead.

Save the file with your preferred changes after you back it up. Go ahead and start the game up, see how it runs.

I have access to a PC with a GeForce 8200 (Below minimum system requirements for the game), and it gets around twenty FPS in low-physics areas. This drops to fifteen when large numbers of icicles are breaking, or during combat.

If somebody can locate the snow particles and figure out how to disable those, I'm certain that would boost FPS dramatically.

Good luck, please let me know how these changes worked out.

I don't see how this helps anyone. It's more or less the same thing as manually setting everything to their lowest settings within the official video options menu ingame.

Better yet would be a tutorial for how to isolate cryostasis so that it has a core all to itself, as most people know the game doesn't use multithreading and therefore suffers in performance on any computer that uses an average multi core processor.
Actually, unless there's stuff going on during the game that would stress the processor that wouldn't do any good anyways. My cpu is always near 0% whenever the game isn't running.