Last update: 09.04.2019

Hello!

In this tutorial I'm gonna explain how can you increase your fps and decrease lag and input lag. Although Alien Swarm is an old game, it's poorly optimized and you can experience lags and fps drops even on better machines. We'll try to get rid of it!

There are some options that have a very high impact on your fps. By reducing them or disabling completely, you can make your game smoother.


Disable V-Sync (Vertical Sync)



V-Sync was created to get rid of screen tearing by syncing your graphic card to the monitor. But it's also making alot of bad things and shouldn't even exist in multiplayer games. Here are some problems caused by V-sync:

- capping fps
- increase input lag
- delay mouse movement (due to input lag)

Also, If you have 60Hz monitor and your fps will drop from 60 to even 59, it will drop again to 30 (double buffering) or 45 (triple buffering) for a moment, causing even more delay. I'm pretty sure none of us wants to play on 30 fps even for a moment.

Why do I need more fps on 60Hz monitor?

More fps decrease input lag, even if your display can't show all those fps. Alien Swarm isn't that fast-paced game, so screen tearing shouldn't be very noticable. But if it's a real problem for you, use G-sync / Free-sync / Fast sync if possible. I tested G-sync on my monitor and it's not causing any input lag. But G-sync is working only when you have fps below your display's refresh rate, so you should cap your fps BELOW your monitor's Hz (58 fps on 60Hz, 118 on 120Hz, 142 on 144Hz etc). I've noticed some input lag when my fps went higher than my refresh rate.

You can use command fps_max to cap your fps on every value you want, but I recommend you to use Riva Tuner Statistic Server (RTSS) instead as it's way more stable, than in-game fps caps.


Resolution



It have the biggest impact on your fps. Lower resolution means less pixels that your graphic card need to create. Here you have some pros and cons about it:

Pros:

- more fps in general
- smaller fps drops during big battles

Cons:

- smaller vision around you. It can (but not must) be a problem on higher difficulties like brutal, where you need to see aliens faster to react properly.
- game is more pixelated

I recommend to play on your native resolution. Change it only if you have nothing else left. If you decided to play on low res, you may also want to change your aspect ratio. 4:3 is giving kinda oldschool look :P

Enable full screen mode



Be sure that you're playing on full screen. In borderless mode, your game is running with its full potential, but also desktop and all other processes that are normally disabled are running as well. This can lower your fps. It's also increasing input lag.


Antialiasing



Second the most fps-affecting option In Alien Swarm. In short, it's making some extra pixels to make smooth edges. The higher resolution your display have, the lower antialiasing you need to get rid of those edges. On 4k display, this option is pretty much pointless, as amount of pixels is enough to cover those edges. I'm playing on 1920x1080 resolution and I can barely see the edges. You don't need this option set to highest. Usually 2x MSAA or x4 MSAA is enough. By disabling it completely, you can increase your fps even by 10-15 in some places.


Shader & Effect Detail



Last options that have big impact on fps. By setting them to low, you'll have almost no shadows in game, aliens will look a bit different and there will be no effects like smoke etc.

I didn't notice big differences with any other option. Also, there's no reason to change Texture Details to low, as it have pretty much no impact on fps. For some people, changing filtering mode can also help. But it gave me like 2-3 fps so it's not a big deal.


Ok, time for options that should be ALWAYS enabled:

Multicore Rendering - Enabled
Paged Pool Memory Available - High

Here's a movie explaining everything about the Nvidia control panel:

https://youtu.be/_KsK55zgUAQ

Changing those settings can boost your fps significally.

Here you some mods from workshop that will Increase your fps and give a more clear vision in game:

http://steamproxy.net/sharedfiles/filedetails/?id=1201160228

https://steamproxy.net/sharedfiles/filedetails/?id=1440291995&searchtext=

Game booster is a program that can improve your pc performance by disabling processes that you don't need while playing. I was using it for a long time on my old pc. It's perfect for lazy people like me who don't want to disable all those processes manually :P

- disable browser and all other internet aplications
- disable all programs and apps that you don't need while playing
- use only one, light antivirus or disable it completely when you're playing games. But don't forget to turn it on when you end up!
- be sure that no one is using your Wifi when you're playing
- if it's possible, don't play through the Wifi. It's usually unstable and can make lag spikes
- always update your graphic card driver to the newest version
- if it's possible, play on servers with higher tickrate

Info in this guide can be used in other games as well.

I hope it will help some people to improve their game experience :)

See you in game!