Diablo 2 Tweak Guide
Posted: August 30, 2000
Written by: Keith "Farrel" McClellan


Diablo 2, as a game, is surprisingly hard on your computer. It uses up a lot of memory and other system resources and has been known to, at times, stutter even on top-end machines. This can be extremely frustrating for people that have gone out and spent several thousand dollars on their computer, but it is even worse for the average gamer - the guy that maybe spends $1500 on a computer every 3 to 4 years but still wants to play his favorite games without too many slowdowns. And considering how hyped up Diablo 2 has been for the past several years, you know this is one of those favorite games. Hopefully, in this guide, I will be able to show you how to get the running at peak performance so that, perhaps, those 'low-enders' can enjoy the game just as much as the computer hobbyists do. In this guide I will be covering the basics (such as choosing a larger installation method) as well as some more advanced techniques. I'll also be throwing in a few tweaks from the rumor ! mill that I've heard have worked for some people but that I personally haven't been able to substantiate.


Downloading patches for a game is always a good idea, particularly if you are having a performance problem. They generally include performance improvements, as well as new features and bug fixes. Diablo 2 (at the time of this writing) is already on version 1.03. You can download it from their official Diablo 2 website here. Read the readme that goes along with the patch before you install it, just in case there are any special instructions or warnings that you need to know about.


Installing new video and sound card drivers can almost always boost in-game performance. Manufacturers are constantly upgrading their software and causing their hardware to run faster and faster as they open up new features of the card and remove redundancies from the internal driver code. This game in particular needs as much of a load taken off the processor as possible, so seriously consider updating all of your drivers to the most recent version. Windrivers is a good place to start looking.


As you can see from the screenshot above, there are three different installation options for Diablo 2 - Single Player (small install, if you can call 500Mb small - installs only what the game absolutely needs to have run off the hard drive), Multiplayer (medium install, about 900 Mb - Installs everything to the hard drive except the movies, which are still run off the cinematics disc), and Full (full install, about 1.5 Gb - Installs everything to the disc and the CD's are only required for authentication). The larger the installation, the better the game is going to perform in most cases.

Installation (cont.)

Even if you only plan on playing the single player version of the game, installing the multiplayer or full versions of the game will still improve performance significantly. As a matter of fact, I would recommend the multiplayer installation (which includes everything but the between act cinematics) to everyone for peak in-game performance, and only install the full version if you have a slow CD-ROM drive or you just have a bunch of extra space.

Video Test and Choosing a Renderer

After the game has installed, it will automatically run the video test and try to determine which renderers the system it is running on is compatible with. There are three options, D3D, DirectDraw, and 3dfx Glide. Here is a rundown of the advantages and disadvantages of each rendering engine:

3dfx Glide - This game was built with Glide in mind, and as such it runs the best under Glide. If you have a 3dfx card, you should definitely be using this renderer - not only is it the fastest one but also the special effects generally look better under it than in the other renderers, since it was designed with this API in mind.

Direct3D - This was hacked into the code at the last minute (or so it appears) and as such it performs worse than the 3dfx Glide implementation. In most cases, however, it is still faster than the DirectDraw implementation, but that can vary from system to system. If you have the choice between Direct3D and DirectDraw, you are going to need to try both and decide which one performs better on your system.

DirectDraw - This was included in the game to allow people with little or no 3D acceleration to also enjoy the game. In some cases this renderer can be faster than the Direct3D renderer simply because D3D came into the game 'late,' and it is most certainly the less buggy of the two implementations. If you are having trouble with D3D, this is the renderer to try.


Within the game there are also some settings, which can be changed to improve the game's performance. The first set of these settings is the sound settings. Here's a rundown of the settings, their possible values, and my recommendation on what to do with them.

3D Sound - This setting, as the name implies, controls whether or not 3D sound is enabled from within the game. Currently, the only sound card that this Diablo 2 feature supports is the Creative Labs Soundblaster Live card - so you can ignore this and the next two settings if you don't own one of these cards. If you are having trouble with lag within the game, particularly during a single player game, try disabling this to increase performance.

More Sound Options...

Environmental Effects - If you own a Soundblaster Live card, this will enable the EAX extensions within the game. If you want to have 3D sound enabled, but you want the game to run a little bit faster and don't mind losing some of the atmospheric sounds, this is the setting to disable.

3D Bias - If you aren't sitting equidistant between your left and right speakers and you are using 3D audio, adjusting this to the left or the right can make it seem like you are sitting in the 'sweet spot' - it isn't quite the same but it's better than nothing.

NPC Speech - This setting controls what you see and hear when a major NPC speaks. The three different options you have here are Audio only, Text only, and Text and Audio. If you are having lag problems when you are speaking to the main NPCs and the sound is stuttering, I would recommend setting this to text only mode. Otherwise, my personal preference is combined text and audio.

Video Settings

This is the second set of settings that can be adjusted to increase in-game performance. Here's a rundown:

Lighting Quality - This setting controls the 'quality' of the lighting within the game (hence the name). The lower the quality, the less of a gradient and the blockier the lighting appears. There are three possible values for this setting; low, medium, and high. High quality lighting looks the best, and low quality lighting looks the worst. I personally prefer the high setting because it looks better, but if you are looking for some extra speed setting this down to medium or low won't take much from the game and will give you a little speed boost.

Blended Shadows - This setting goes hand in hand with the Lighting Quality setting in that it controls how the shadows look and whether or not they blend with the light sources (a more natural look) or if they are hard and fake looking. I personally leave this enabled (it's an on/off kind of thing) but once again, by disabling it you can get a bit of a speed boost.

Perspective - This setting is an absolute abomination - all it does is warp the screen in the center to make the game 'look' like it's 3D even if it isn't. Only enable this setting if you like playing a game that looks like it's being projected through a crystal ball - I don't, so I leave it off. Turning it on gives a slight performance hit as well, so think of it as a double treat to disable this crappiest of crappy 'features.'

Automap Settings

This is the last list of settings that have any effect whatsoever on the speed of the game - however, these settings also have the least effect of any of the settings, so if you are having a problem with the speed of the automap just leave it off unless you need it - that's the best way to go. Here's the info anyway though...

Automap Settings

Fade - This setting controls how bright the automap is in comparison to the actual game. There are three possible values for this setting; no, center, and everything. No and everything are the best settings - the only difference is that setting this to no is brighter than setting it to everything. Center, as a general rule, because it recalculates the brightness of the automap all the time, slows the computer down a bit and I wouldn't recommend it. I personally find it ugly anyway.

Center When Cleared - The automap, as you might already know, can be moved independently of the character. When this is enabled, if you turn the automap 'off' and then back on again, it re-centers the map on the character. This is a personal preference setting so do as you will, but I have it enabled.

Show Party - This setting determines if your party members (and NPCs) are shown on the map or if they are invisible to you. Disabling this might give a very slight performance increase, particularly if there are a lot of people in your party in a multiplayer game, but otherwise I see no reason not to leave this enabled.

Show Names - This setting shows the names of you, your party members, and any significant NPCs on your map. Just like the above setting, during a large multiplayer game I could see how this might cause a very minor speed impact, I personally don't think it is significant enough to worry about so I recommend leaving this enabled.


I've heard of a few other tweaks that may specifically improve performance, but I haven't verified them so these tweaks should be taken with a grain of salt. The first tweak is to increase the swap file size to at least 256 MB. Personally, I have no idea why this would affect performance if you already have a permanent swap file, but it has worked for some people. Another tweak includes turning down the read-ahead optimization for the CD-ROM drive (system applet in the control panel) to half or no read ahead optimization. This seems like something that should do the exact opposite of what we want, but it has worked for some people (they may have old CD-ROM drives). As I already said, use these tweaks at your own risk - I have no idea how well they will work. When I tried them they didn't help, but at least they didn't break my system.


Hopefully, this guide has helped you improve the performance of Diablo 2 on your system. If you are still having problems with the speed of your system, you have a couple of options. The first, best, and cheapest option would be to tweak out your entire system using our tweak guides. If you have already tried that and things are still not running the way you would like, you might consider adding more RAM to your system or possibly upgrading either your CPU or video card. Now, I personally wouldn't recommend upgrading your system for one game, but if you play a lot of games and you really have to work with them to get them to run well that is definitely an option. As always, feel free to e-mail me with your comments and questions - I can't always promise a response but I do read every email I receive.

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