Tips for Video Optimization

The X-ray engine was developed EIGHT years ago, so it is not designed to do the
things modern PC games can. Widescreen monitors and 4GB GPU’s did not exist at
the time. Misery takes best advantage of Modern hardware capabilities and squeezes
the maximum possible amount out of the X-ray engine. X-ray only uses 1 CPU Core so
Boost single core CPU speed is the primary driver of performance provided the
necessary RAM is available.* Higher FOV’s require considerably more resources to
draw and I recommend staying as close to the default FOV (55) as you can.

If you have the game running stable and are just trying to optimize things, make a
backup copy of your _appdata_ user.ltx so you can go back to it if you hit a wall.

While trying to set up a new GPU I nailed down a couple things to help new GPU
owners and first time Misery Stalkers get their rigs set up. If you want to start fresh with
the least demanding and arguably most compatible set of video settings do the
following: Go to C:\SteamLibrary\SteamApps\common\Stalker Call of
Pripyat\_appdata_ (substitute your particular install location) and delete tmp.ltx and
user.ltx. When you load the game you will have the base low video options set.

Each time you want to try a new set of parameters out do the following: Select Low,
Medium, High, or Extreme base settings, apply. Before going out of the game and
restarting adjust anything else you want changed. Apply again. Exit game and go to
the above directory. Delete the tmp.ltx. Copy the user.ltx to the SAME directory; it will
make a copy 2. Click once on the second copy and change the name to tmp. After you
have done this a couple times it will take you very little effort to repeat and things will
speed along.

Note: While AMD cards are optimized to more efficiently use HDAO, it is still extremely
demanding so I recommend HBAO (at the Low level) for Nvidia and AMD GPU users
or none at all.

There is also a leftover copy of user.ltx in the main COP directory. I recommend
deleting it as it can cause conflicts. If you make the mistake of verifying your game
cache in Steam, it will replace this missing original version of user.ltx and you may
notice a dramatic performance hit. Delete it again.

Start game and try your new settings. Yes, you will have to bind all your keys and
change your non-video options back after deleting both files, but only once. I don't
know why, but if you just change options and don't replace the tmp.ltx with the changed
user.ltx, some or all of your changes will display in game, but won't actually be applied.
The things that are most RAM and FPS consuming are (in order of Priority):
Antialiasing,
Shadows,
Sun rays,
Dynamic Lighting.

Turning off SSAO and each of the above can Improve your frame rates (FPS). Each
time you try a new set of settings repeat the above procedure and be assured that the
settings you ticked off are actually being applied.

Experience has shown that for most hardware configurations you are best off either
going for broke with Highest level of DX11 rendering or Lowest with basic Static
Lighting. Nothing in between generally runs stable. Static lighting loads, reloads, and
saves much faster too.

The main menu screens ignore the in-game configuration settings and with a high tier
GPU you may draw 7500 FPS or more causing a slight high pitched squeal in the
audio background. Some older Monitors and/or GPU’s may require the 60HZ option be
checked off to run stable. I don’t use vertical sync or the 60 HZ option and rely on a
third party Frame Limiter to control both Main Menu and gameplay FPS. You can use
whatever you prefer for your GPU, I use Dxtory’s trial version because it works on both
AMD and Nvidia GPUs. Experimenting on an older rig, I determined that combining
Static Lighting and Frame Limiting at 30 FPS you can achieve stable FPS performance
at up to 200 Meters higher Alife switch_distance.

Frame limiting below your Monitors maximum rated refresh rate and at least 5 below
your average minimum in game performance will result in more stable frame rates, less
stutter, and a much cooler climate in your gaming room. Chernobyl is not in the tropics,
why should you have burn marks on the table under your laptop or raise the ambient
temperature in the room dramatically just playing a game? Hearing those telltale
sounds in the background is critical to survival. Don’t make your rig work harder and
die in the zone because you couldn’t hear the dogs barking over your CPU/GPU
fans…

Once you have your video options optimized, you can see how much your rig can
stand Alife wise. Editing C:\Program Files (x86)\Steam\steamapps\common\Stalker
Call of Pripyat\gamedata\configs\alife.ltx with notepad (or better yet FREE Notepad++)
you can easily and quickly adjust your switch_distance up or down to achieve desired
frame rates.
The text line will originally look like this:

switch_distance = 300 ; 950 ; 150 ; 350 ; 450 ; 500 ; 550 ; 600 ; 850 metres

Only the first number after the = sign matters; all after the first semicolon is ignored.
Change your switch_distance up by 50 at a time and restart the game. RUN across the
landscape and when your FPS stops being a steady average 30 FPS make a note of
the switch_distance and reduce it by 100. This should give you your optimal
switch_distance. The artificial intelligence (AI) load is higher on the Jupiter map than in
Zaton. I typically use 100 Meters lower switch_distance for Jupiter than at the games
start in Zaton. Staying at least 50-100 meters below your maximum switch_distance
will prevent the need to readjust as you switch maps.

There is a great benefit to playing at higher switch_distances. The higher your

switch_distance the less often you will have stutter and lag as you traverse the maps.
Every time your travel brings a new group of NPC’s or Mutants into your Alife circle
your system has to keep up with both drawing them and their AI coming online. The
more which is already in your circle, the less changes occur and thus steadier FPS and
less stutter. You will still have dips in FPS; they will be less dramatic and frequent at
higher switch_distances.

While you are in alife.ltx edit the objects_per_update down from 10 towards 1. This
factor controls how much is updated on the offline maps at once. It will reduce the
duration of the remaining stutters and lag.

* My system needs at least 8GB of DDR RAM to run Misery and all the other stuff I
keep running in background. If you don’t have 8GB, you will need to close some or all
background programs (Internet Explorer, your E-mail client, etc.) and/or reduce some
Graphics and/or game options like Alife switch_distance until you achieve the FPS
performance you need and stable play.

p.s. Microsoft update KB2670838 can cause CTD's or inability to start game with DX10
or DX11 renderer selected. The update can be uninstalled, or you can follow the
directions in this GOG article for the same effect:
http://www.gog.com/forum/stalker_series/stalker_clear_sky_possible_fix_for_dx10_cra
shes_windows_7_due_to_kb2670838_without_uninstalling_t .

p.p.s. Windows 10 divides the processing between cores/threads much more evenly
even on the xray engine. However, this does not make core priority tweaks pointless.